DISSERTATION on
METASTATIC STATUS OF LYMPHNODES FROM RADICAL SURGICAL RESECTIONS - ROLE OF CYTOKERATIN AS AN
ADJUVANT TO STANDARD STAINING METHOD submitted in partial fulfillment of the requirements for the degree of
Doctor of Medicine
(BRANCH-III) M.D. PATHOLOGYRegister No.:201713301
THE TAMIL NADU DR. M.G.R. MEDICAL UNIVERSITY CHENNAI
TIRUNELVELI MEDICAL COLLEGE TIRUNELVELI
MAY 2020
CERTIFICATE
This is to certify that the dissertation titled “METASTATIC STATUS OF LYMPHNODES FROM RADICAL SURGICAL RESECTIONS-ROLE OF CYTOKERATIN AS AN ADJUVANT TO STANDARD STAINING METHOD” is a bonafide work done by Dr.S.AISWARYA NIVEDHITHA, Post Graduate Student, Department of Pathology, Tirunelveli Medical College, Tirunelveli – 627011, in partial fulfilment of the university rules and regulations
for the award of MD DEGREE in PATHOLOGY BRANCH-III, under my guidance and supervision, during the academic period from 2017 to 2020.
DR. S.M.KANNAN, MS .MCh (Uro)., Dean,
Tirunelveli Medical College, Tirunelveli-627011.
CERTIFICATE
I hereby certify that this dissertation entitled “METASTATIC STATUS OF LYMPHNODES FROM RADICAL SURGICAL RESECTIONS-ROLE OF CYTOKERATIN AS AN ADJUVANT TO STANDARD STAINING METHOD” is a record of work done by Dr.S.AISWARYA NIVEDHITHA, in the Department of Pathology, Tirunelveli Medical College, Tirunelveli, during her postgraduate degree course period from 2017- 2020. This work has not formed the basis for previous award of any degree.
Prof.DR.K.SWAMINATHAN. MD, Department of Pathology, Tirunelveli Medical College, Tirunelveli- 627011
Prof.DR.K. SHANTARAMAN.MD, Professor and Head,
Department of Pathology, Tirunelveli Medical College Tirunelveli- 627011.
DECLARATION
I solemnly declare that the dissertation titled “METASTATIC STATUS OF LYMPHNODES FROM RADICAL SURGICAL RESECTIONS-ROLE OF CYTOKERATIN AS AN ADJUVANT TO STANDARD STAINING METHOD” was done by me at Tirunelveli Medical College, Tirunelveli– 627011, during the period September 2017 to august 2019 under the guidance and supervision of Prof.DR.K.SWAMINATHAN, MD, to be submitted to The Tamil Nadu Dr. M.G.R.
Medical University towards the partial fulfilment of requirements for the award of MD DEGREE in PATHOLOGY BRANCH-III.
Place : Tirunelveli Date :
Dr.S.AISWARYA NIVEDHITHA, Register No: 201713301
Post Graduate Student, Department of Pathology Tirunelveli Medical College,
Tirunelveli – 627011.
ACKNOWLEDGEMENT
I thank Professor Dr.S.M.KANNAN, M.S MCh, Dean, Tirunelveli Medical College, for having permitted me to conduct the study and use the hospital resources in the study.
I express my heartfelt gratitude to Professor Dr. SHANTARAMAN. K. MD, Professor and Head, Department of Pathology, for his inspiration, advice and guidance in making this work complete.
I am extremely thankful to Professors DR. SWAMINATHAN .K. M.D., DR.SURESH DURAI. J. M.D., DR.ARASI RAJESH, M.D, DR.VASUKI, M.D, my Associate Professors DR.V.BHAGYALAKSHMI, M.D, DR.J.JOHNSY MERLA, MD, Department of Pathology, for guiding me during the period of study.
I am extremely thankful to Assistant Professors Dr.Hidhaya Fathima M.D, Dr.Sindhuja M.D, Dr.Mahalakshmi M.D, Dr.Dina Mary MD, Dr. Dharma Saranya MD, Dr.Chandhru Mari MD, Department of Pathology, for guiding me academically and professionally during the period of study.
I also thank all the lab technicians and my fellow postgraduates for their cooperation which enormously helped me in the study. Without their humble cooperation, this study would not have been possible.
I thank GOD AND MY FAMILY, for blessing me not only in this study, but in all endeavours of my life.
CERTIFICATE – II
This is certify that this dissertation work title “METASTATIC STATUS OF LYMPHNODES FROM RADICAL SURGICAL RESECTIONS-ROLE OF CYTOKERATIN AS AN ADJUVANT TO STANDARD STAINING METHOD” of the candidate Dr.S.AISWARYA NIVEDHITHA with registration Number
201713301 for the award of M.D. Degree in the branch of PATHOLOGY (III).
I personally verified the urkund.com website for the purpose of plagiarism check. I found that the uploaded thesis file contains from introduction to conclusion page and result shows 16 percentage of plagiarism in the dissertation.
Guide & Supervisor sign with Seal.
TABLE OF CONTENTS
Sl.No. CONTENT Page No.
1. INTRODUCTION 1
2. AIM & OBJECTIVES OF THE STUDY 3
3. REVIEW OF LITERATURE 4
4. METHODOLOGY 53
5. OBSERVATION AND RESULTS 59
6. DISCUSSION 85
7. CONCLUSION 89
8. BIBLIOGRAPHY 9. ANNEXURE
MASTER CHART
LIST OF ABBREVIATIONS USED IN THIS STUDY
ACB ADENOCARCINOMA BLADDER
ACE ADENOCARCINOMA ENDOMETRIUM ALCL ANAPLASTIC LARGE CELL LYMPHOMA AMC ATYPICAL MEDULLARY CARCINOMA DAB DIAMINO BENZIDINE
ENE EXTRA NODAL EXTENSION
FNAC FINE NEEDLE ASPIRATION CYTOLOGY H&E HEMATOXYLIN AND EOSIN
HEV HIGH ENDOTHELIAL VENULE IDC INVASIVE DUCTAL CARCINOMA
IDLC INVASIVE DUCTO LOBULAR CARCINOMA IHC IMMUNOHISTOCHEMISTRY
ILC INVASIVE LOBULAR CARCINOMA MDACCo MODERATEDLY DIFFERENTIATED
ADENOCARCINOMA COLON
MDACCx MODERATED LY DIFFERENTIATED ADENOCARCINOMA CERVIX
MDACS MODERATEDLY DIFFERENTIATED ADENOCARCINOMA STOMACH
MDSCCBM MODERATEDLY DIFFERENTIATED SQUAMOUS CELL CARCINOMA BUCCAL MUCOSA
MDSCCL MODERATEDLY DIFFERENTIATED SQUAMOUS CELL CARCINOMA
MDSCCT MODERATEDLY DIFFERENTIATED SQUAMOUS CELL CARCINOMA TONGUE
MuADCS MUCINOUS ADENOCARCINOMA STOMACH NOS NOT OTHERWISE SPECIFIED
PANCK PAN CYTOKERATIN
PapCA/PTC PAPILLARY THYROID CARCINOMA
PDACS POORLY DIFFERENTIATED ADENOCARCINOMA STOMACH
PET POSITRON EMISSION TOMOGRAPHY
SPAC SEROUS PAPILLARY CYSTADENOCARCINOMA
SPECT SINGLE PHOTON EMISSION COMPUTED TOMOGRAPHY VEGF VASCULAR ENDOTHELIAL GROWTH FACTOR
WDACCx WELL DIFFERENTIATED ADENOCARCINOMA CERVIX WDACE WELL DIFFERENTIATED ADENOCARCINOMA
ENDOMETRIUM
WDACI WELL DIFFERENTIATED ADENOCARCINOMA ILEUM WDACS WELL DIFFERENTIATED ADENOCARCINOMA
STOMACH
WDEACOv WELL DIFFERENTIATED ENDOMETRIOID ADENOCARCINOMA OVARY
WDSCCA MODERATEDLY DIFFERENTIATED SQUAMOUS CELL CARCINOMA ALVEOLUS
WDSCCBM WELL DIFFERENTIATED SQUAMOUS CELL CARCINOMA BUCCAL MUCOSA
WDSCCF MODERATEDLY DIFFERENTIATED SQUAMOUS CELL CARCINOMA FOOT
1
INTRODUCTION
Cancer metastasis is a complex, multistep process that involves dissemination of cancer cells from the primary site to distant organs. Lymph nodes are initial sites for metastasis in many solid tumours[1].
Metastasis, the spread of a tumour cells from its primary lymph node (LN) to distant organs, is the most fearsome aspect of cancer. Patients presenting with metastatic disease or those developing metastases after successful management of primary tumour carry a universally grave prognosis.
Metastasis is the cause of 90% of cancer deaths. Tumour cell invade either the blood or the lymphatic vessels to access the general circulation and then establish in other (visceral) tissues. Hence, nodal status is a significant predictor for survival of patients with malignant tumours[2].
Though surgical resection done early, some patients get recurrence and die of cancer. So it is our thought that those with an early stage of malignancy and died, might have got occult metastasis in their nodes at the time of initial diagnosis. Those occult metastasis can be identified by evaluating deeper levels of blocks by or IHC with epithelial markers such as cytokeratin[3].
Cytokeratin is a family of water insoluble intracytoplasmic structural proteins that are the dominant intermediate filament protein of epithelial and hair forming cell, also present in epithelial tumours, within a cell, form a dense network radiating from the nucleus to the plasma membrane which helps cells
2
to resist mechanic stress. Pan cytokeratin immunohistochemical stain that reacts to a wide range of keratins includes AE1/AE3, MNF116.
AE-3 is a broad spectrum anti pan-cytokeratin antibody cocktail, which differentiates epithelial tumours from non epithelial tumours. The pan cytokeratin antibody cocktail is a well-known broad spectrum immune histochemical epithelial marker for screening for epithelial differentiation in tumour and their metastases. Positive pan cytokeratin staining with the antibody in the lymph node or bone marrow can be useful for identification of metastasis[4].
Hence the present study is carried out with the aim to establish the utility and expression of immunohistochemistry marker (pan cytokeratin) in
identifying occult metastasis in lymph nodes.
3
AIM
To determine the effectiveness of immunohistochemistry (Pan cytokeratin) as an adjuvant in detecting occult metastasis in lymph nodes
OBJECTIVES:
1. To Establish the role of cytokeratin in detecting occult metastases in lymph nodes which are missed in routine H-E staining.
2. To understand their aid in accurate staging of the disease, thereby determining further treatment plan of such patients. Thus, improving the prognosis and survival of patients with malignancies.
4
REVIEW OF LITERATURE
LYMPHNODES - FUNCTION AND THEIR DISTRIBUTION:
The lymph node is one of the important anatomic components of the immune system[5, 6]. They are encapsulated and act as centres of antigen presentation, lymphocyte activation, differentiation and proliferation. These are facilitated by complex trafficking of cells and lymphatic flow via the structure [7]. They generate mature, antigen-primed B and T cells, filter particles, including microbes, from the lymph by the action of macrophages. Normal young adult body has up to 450 lymph nodes, of which 60–70 are found in the head and neck, 100 in the thorax and as many as 250 in the pelvis and abdomen.
They are especially numerous in the neck, mediastinum, posterior abdominal wall, abdominal mesenteries, pelvis and proximal regions of the limbs (axillary and inguinal lymph nodes). Most of them lie close to the viscera, especially in the mesenteries.
Nodes in most of the regions drain the body’s surface, digestive system, or respiratory system. All these areas are having high-risk for the entry of foreign pathogens. Lymph nodes are abundant and accessible to palpation in the axilla, groin and femoral region, and neck. Deep sites that are not accessible for palpation include, those associated with the trachea and bronchi in the thorax, and with aorta and its branches in the abdomen.
5 MICROSTRUCTURE
Lymph nodes are small, oval or kidney-shaped bodies. They are 0.1–2.5 cm long, lying along the course of the lymphatic vessels. Each of which usually has a slight indentation on one side- the hilum, through which blood vessels enter and leave. And also the efferent lymphatic vessels leave the node via the hilum. Several afferent lymphatic vessels enter the capsule around the periphery of the lymph node. Lymph nodes have a cellular cortex and a medulla, which contains a network of minute lymphatic channels called sinuses through which lymph from the afferent lymphatics is filtered, to be collected at the hilum by the efferent lymphatics. The cortex is absent at the region of hilum, where the medulla reaches the surface. The capsule of lymph nodes are composed of collagen fibres, elastin fibres (particularly in the deeper layers) and few fibroblasts. Trabeculae of dense connective tissue extend radially into the node from the capsule. They are continuous with a network of fine type III collagen fibrils (reticulin), which branch and interconnect to form a very dense network in the cortex of the lymph node and providing attachment for various cells, such as dendritic cells, macrophages and lymphocytes. There are only fewer fibres in the germinal centres of follicles.
6
Figure -1 structure of lymph node; Adapted from - Gray’s anatomy,41st edition.
VASCULAR SUPPLY
Arteries and veins supplying lymph nodes pass through the hilum, give off straight branches that traverse the medulla and send out minor branches as they do so. In the cortex of lymph nodes, arteries form dense arcades of arterioles and capillaries in numerous anastomosing loops, and then returning to highly branched venules and veins. Capillaries are especially profuse around the follicles, which contain only fewer vessels. Post capillary HEVs are numerous particularly in the para cortical zones. They form an important site of blood- borne lymphocyte extravasation into lymphoid tissue[8]. These specialized endothelial cells have receptors that bind intravascular lymphocytes as they pass by and facilitate their migration into the reticular meshwork[9]. Veins leave a
7
node through its principal trabeculae and capsule, and drain them and also the surrounding connective tissue.
LYMPHATIC TRUNKS AND DUCTS
All lymphatic vessels coalesce to form larger trunks or ducts, which then drain into the venous system at sites in the neck where the internal jugular veins join the subclavian veins to form the brachiocephalic veins.
Lymph from the right side of the head and neck, the right upper limb, and
the right side of the thorax is carried by lymphatic vessels that connect with veins on the right side of the neck.
Lymph from all other regions of the body is carried by lymphatic vessels that drain into veins on the left side of the neck.
HISTOLOGY
The three major regions of a lymph node are cortex, paracortex, and medulla[10]. The cortex is located just beneath the capsule and represents the compartment where most lymphoid follicles reside and is composed of mainly B lymphocytes and also follicular dendritic cells. The medulla which is close to the hilum and grows in the form of cords. It is rich in lymph sinuses, arteries, and veins but contains only a minor lymphocytic component that is a combination of B and T lymphocytes. Appearance of the follicles varies according to their state of activity. Primary follicles appear as round aggregates
8
of small lymphocytes with little cytoplasm, secondary follicles appear following antigenic stimulation and they are characterized by the presence of germinal centers surrounded by mantle zones. The germinal center cells are mostly of B lymphocytes known as follicular center cells (centroblasts and centrocytes or small and large cleaved and noncleaved cells), macrophages, and follicular dendritic cells, but a population of T follicular–helper cells also present normally in this compartment. The germinal center contains pale-staining large cells on hematoxylin and eosin sections and that are normally highly proliferative and shows polarization toward the side of antigen stimulation. The surrounding mantle zone B lymphocytes are smaller in size.
Figure -2 Adapted fromWheater’s functional histology, sixth edition- Barbara young, Geraldine O’Dowd
9
The Afferent lymphatic channels enter the convexity of the lymph node, and fluid drains into the peripheral subcapsular sinuses. The sinuses of the lymph node are lined by macrophages, and these cells filter out the debris from the fluid. The fluid percolates through the sinuses and emerges via an efferent lymphatic channel at the hilum of the node. Follicles in the cortex of the lymph node are the site of B-cell activation. The intervening paracortical areas are the main sites of T cells in the lymph node.
VARIOUS ROUTES OF METASTASIS
At an early stage of malignancy, malignant cells are confined to the primary site within the boundary of certain surrounding tissues. When the disease progresses, some cancer cells, as the result of genetic/ epigenetic predisposition, and the influence of environmental interaction/stimulation, and indeed the combination of these elements, become aggressive and start to breach the surrounding structure. These cells would either directly invade the surrounding tissue, or disseminate via lymphatic and haematogenous routes.
Direct invasion result in the spreading of cancer cells to surrounding tissues and adjacent organs. For example, local invasion of prostate cancer, can affect the erectile nerves, seminal vesicles, bladder and rectum nearby the prostate[11].
The lymphatic and vascular routes differ from cancer to cancer according to their primary sites of lesion, however, they frequently result in systemic spread of malignant cells to distant organs, such as bones, lung, and liver.
10
Both lymphatic and haematogenous dissemination occur, even during early stages of the malignancy, and are seen in a vast majority of the patients who have an advanced malignancy. Brain, bone, lung and liver are the most common haematogenous sites from certain solid tumours.[12, 13]
The process of metastasis is complex, which incorporates multiple cells, factors and stages. During the development and progression of primary malignancies, certain clones of malignant cells will have the required genotypic and phenotypic characteristics to enable themselves to interact with the local microenvironment. They release VEGF to initiate angiogenesis, and thus enhancing the blood flow to the tumour. The stromal cells are rich sources of protein factors that directly act on cancer cells thus helping the growth of tumours and dissemination of cancer cells. On the other hand, some of the stromal cell derived factors will directly promote angiogenesis, thus supporting the growth and spread of an aggressive tumour. An example of these stroma- derived protein factors are hepatocyte growth factor (HGF), which is a cytokine secreted by the stromal cells, which has been implicated in the angiogenesis and the dissemination of malignant cells[14] .The disruption of intercellular adhesion in the malignancy causes some malignant cells to detach from the mass called detachment, followed by these cells invading via the extracellular matrix, a process called invasion which incorporates the motility, migration of malignant cells and breakdown of extracellular matrix. Some malignant cells
11
will penetrate the blood vessels and enter the circulation called intravasation.
From this point, cells move away from the primary site and circulate in the blood where, they would encounter resistance by the immune system and the mechanical stresses of blood flow. Some malignant cells will eventually survive and adopt a process to leave the circulation, called as extravasation, in which cells adhere and penetrate the blood vessel again (virtual reversal of the intravasation process). Once the malignant cells escape from the circulation, they have to survive and finally develop a secondary malignancy at other site.
This complex process also needs the integration of multiple factors and events, such as invasion of malignancy, angiogenesis and the interaction between malignant cells and the local microenvironment at a distant site/organ.
LYMPH NODE METASTASIS OF MALIGNANCY:
Lymph nodes are the most common site of metastasis of malignancy and constitute the first clinical manifestation of the disease sometimes [15, 16].
Presence of malignant cells within efferent lymph vessels and/or extranodal adipose tissue, have prognostic significance.
Any malignant tumour can give rise to lymph node metastases, but the incidence varies depending upon the tumour type. It is common with carcinomas (epithelial malignancies), malignant melanomas, and germ cell tumours, rare with sarcomas and central nervous system tumours. Large cell lymphomas primary in an organ (such as stomach and thyroid) sometimes
12
involve the regional nodes in a pattern consistent with metastatic spread and the pattern of lymph node infiltration of ALCL may mimic a metastasis. An additional diagnosis to be considered in a lymph node involvement by metastatic tumour is malignant mesothelioma. Most of the primary tumours are located in the peritoneum than the pleura, regardless of the location of the lymph nodes[17]. Nodal metastases of squamous cell carcinoma have a particular tendency to undergo cystic changes. When these changes are prominent in a lymph node located in the neck, a mistaken diagnosis of branchial cleft cyst maybe made. The location of a lymph node involved by metastatic carcinoma gives important clues about the possible site of the primary tumour.
The majority of malignant tumours metastatic to upper cervical lymph nodes arise from the upper aerodigestive tract. The sites well known for harbouring small and clinically undetectable primaries in the presence of cervical lymphadenopathy are the nasopharynx and retrotonsillar pillar[18-20].
Midcervical nodes containing features of papillary carcinoma are usually of metastatic thyroid carcinoma, a possibility that becomes a virtual certainty in the presence of psammoma bodies. These papillary tumours may also originate from salivary gland, thymus or female genital tract. Squamous cell carcinomas present in lymph nodes of this region usually arise from upper aerodigestive tract, especially pharynx and larynx[21] .Most of the carcinomas metastatic to supraclavicular lymph nodes arise from the lung or breast. Other sources of
13
metastases to this group of lymph nodes, particularly if located on the left side, are carcinoma of stomach, pancreas, prostate, and testis[19, 22]. They reach the node via the terminal collecting lymphatic trunks. Those nodes involved by intra-abdominal carcinomas are referred as Virchow or Troisier nodes[23]. The majority of metastatic tumours in axillary nodes of adult females are breast carcinoma and malignant melanoma[24, 25]. Lung carcinoma should also be considered, especially in older patients with a history of smoking[26].
Metastasis in inguinal nodes are mostly of carcinomas of external genital organs or malignant melanomas of the lower extremities, but only rarely from the internal abdominal organs such as ovary, uterine cervix, and anal canal, even less commonly from the testis, unless direct extension to the scrotal skin has occurred[27].
Some of the benign conditions of lymph nodes that can mistakenly be interpreted as metastatic carcinoma. They include hyperplastic mesothelial cells[28], megakaryocytes[29], signet ring sinus histiocytosis[30], the related nodal muciphages and mucicarminophilic histiocytosis[31,32], florid anthracosis / anthracosilicosis[33].
METHODS OF DETECTION OF METASTASIS IN LYMPHNODES:
Non invasive radiological procedures are often done during the evaluation of malignancies. Lymph nodes are usually diagnosed as having metastasis by CT and MRI when their short axis is >10 mm in diameter [34].
But Such size criteria, shown to be uncertain [35]. The detection of metastasis
14
in unenlarged (occult) nodes are frequently low by PET and SPECT. Especially small nodal metastases < 5 mm are frequently missed by PET scan in breast malignancy[36].
The cytological evaluation of lymph nodes is a cost-effective simple procedure which may provide valuable information regarding the disease process, including both neoplastic and non-neoplastic conditions. Cytological evaluation of lymph nodes may be done either by fine-needle aspiration cytology (FNAC) or preparation of imprint or touch smears.
Fine-needle aspiration cytology has become a well-established method of diagnosis for metastasis to the lymph nodes[37]. This simple technique has gained wide acceptance since it offers several advantage to patients and physicians. The technique is relatively painless and minimally invasive, produces fast results and its accuracy can approach that of histopathology in providing a definite diagnosis[38]. It is now the first-line investigation technique for the diagnosis of significantly enlarged lymph node. This method is applicable both to the lesions that are easily palpable and also to the lesions which are deeply located under radiological guidance. The results of fine-needle aspiration (FNA) compare favourably with those of tissue biopsies in some situations, the aspirate has qualities of a micro biopsy [39]. However, FNAC is not a substitute for conventional histopathology, and it should be regarded as an essential component of preoperative/pretreatment diagnosis, when correlated clinico - radiologically and with other investigations[40].
15
Immunohistochemical techniques using anticytokeratin antibodies can identify the lymph node metastases which are missed on routine Haematoxylin and eosin staining of tissues ,since cytokeratin proteins are the essential constituents of the cytoskeleton proteins of both normal and malignant epithelial cells in the lymph nodes, they act as reliable markers for the epithelial origin of cells[41]. It is established that higher diagnostic accuracies can be achieved using multiple serial sections and by IHC [42, 43].
METASTASIS OF VARIABLE MALIGNANCIES TO REGIONAL LYMPH NODES:
BREAST CARCINOMA
Grossly, all lymph nodes present in an axillary dissection specimen need to be identified and submitted for histopathological evaluation to identify metastases [44]. The total number of lymph nodes is an important prognostic factor. Gross examination by itself is unreliable for identifying the number of lymph nodes involved by malignancy, as their number is usually underestimated.
In general, invasive breast carcinoma is associated with increased risk of axillary lymph node metastases. Metastases to lymph nodes reach via afferent lymphatics and enter sinuses. Hence in nodes with partial involvement, the metastases particularly have a sinusoidal distribution. With more extensive involvement, the architecture of the lymph nodes will be progressively replaced.
The microscopic patterns of nodal metastases reflect the histologic types of the
16
primary breast malignancy, with exceptions in ≤ 5% of cases [45]. The
recognition of blood vessel and lymphatic invasion in specimens is important, because the presence of either strongly correlates with the presence of nodal metastases [46]. The most common type of breast malignancy, representing up to 80% of all cases is infiltrating ductal carcinoma, not otherwise specified(NOS). This type is often accompanied by abundant fibrosis, both in the breast and in lymph node metastases. Nodal metastases also mostly reproduce the nests and cords pattern of the primary breast malignancy. Fibrosis around the carcinoma cells is moderate, however, thick bands of collagen can also occur occasionally. Cytologically, metastatic ductal epithelial cells vary from cuboidal, monomorphic and relatively bland to large and highly pleomorphic nuclei with frequent mitoses. The cytological features of malignancy in the lymph node strongly correlate with the grade of the primary breast malignancy. The response to the invading malignancy in the lymph node, in addition to the desmoplasia, can take the form of enlarged follicles with formation of reactive germinal centers, excessive histiocytosis /granuloma formation. Many variants of carcinoma of the breast exist, some of which less commonly metastasize to lymph nodes such as papillary, mucinous, tubular whereas others more frequently metastasize to lymph node such as inflammatory.
17
Lobular carcinoma metastasizing to lymph nodes is difficult to recognize in routinely stained H&E tissue sections. Invasive lobular carcinoma of the breast is composed of homogeneous small bland cells that does not form duct- like structures, instead the cells are arranged in Indian file pattern. They are small cells with scant cytoplasm with round or ovoid open nuclei, fine inconspicuous nucleoli and infrequent mitoses. Occasionally, they show an intracytoplasmic mucin-containing vacuoles and an eccentrically placed nuclei, which are typical of signet ring carcinoma cells. Focal signet ring cell differentiation is frequent in lobular breast carcinoma, although it rarely involves 50% or more of the total cell population. In the lymph nodes, lobular carcinoma metastatic cells can appear as dis cohesive and may not be associated with desmoplastic reaction. Extensively involved lymph nodes may resemble lymphoma at low power examination. At the other extreme, axillary lymph nodes with focal involvement of metastatic lobular carcinoma can be extremely difficult to recognize. Metastases are mostly distributed in the sinuses and sometimes deep in the cortex or the medulla, without initial involvement of the marginal sinus. When the metastases are sparse, they consist of single cells or arranged in small cell clusters that may closely resemble histiocytes.
Chemotherapy can change the cytological appearance of metastatic cells and also alters lymph nodes. Chemotherapy can cause carcinoma cells to develop foamy cytoplasm and closely resemble lipid-laden histiocytes.
18
However, the malignant cells usually retain their nuclear atypia, which is helpful for their identification and distinction from the histiocytes.
Chemotherapy depletes lymph nodes of the lymphoid tissue so that only the supporting framework of the node remains, with or without residual islands of the lymphoid tissue. Both the size and location of the breast cancer metastases within an individual axillary lymph node have prognostic significance. The prognosis is worse when lymph node metastases extend through the capsule into the perinodal adipose tissue called as extranodal extension. In general, presence of extranodal extension correlates with the size of metastases that is, being most likely in cases with larger metastases.
ADENOCARCINOMA STOMACH
The rich mucosal and submucosal lymphatic plexus of the stomach is often invaded by the tumour and from here it can spread to perigastric, periaortic, and celiac axis-related nodes[47]. Tumours which are present in the distal third of stomach show high incidence of hepatoduodenal nodes involvement [48]. The presence of mucosal lymphangiectasia has been found to be associated with regional lymph node metastases[49]. The incidence of detection of lymph node metastases is more influenced by the method used to search them, it is significantly higher with a comprehensive fat-clearing method[50,51] or if the microscopic sections are evaluated immunohistochemically using cytokeratin[52].
19 MUCINOUS ADENOCARCINOMA
Signet ring cell carcinoma cells tend to grow in singles and have bundant intracytoplasmic mucin distending the cells and pushing the nuclei to the periphery, imparting a signet ring cell appearance. Minor areas may have extracellular pools of mucin. Glands are not formed. Hence these cells can be missed, particularly at low-power magnification. Even at high-power magnification, these cells can be difficult to distinguish from histiocytes within the lymph node sinuses. Mucinous carcinomas usually have predominant areas of pools of mucin that may vary in size, some being visible macroscopically [53, 54]. Some of the mucin pools may lost part / all of their cellular lining, and appear as entirely acellular. The residual cells which are lining the lakes of mucin may appear dysplastic, with only having moderately atypical nuclei.
It must be emphasized that immunohistochemistry is more needed in some lymph nodes for detecting the presence of occult micro metastases of signet ring cell carcinomas and mucinous carcinomas. This is particularly essential for diagnosing single cell metastases of signet ring cell carcinoma. Use of cocktail of keratin antibodies is more helpful for this purpose.
PAPILLARY CARCINOMA THYROID
Papillary carcinoma thyroid has a great propensity to metastasize to cervical nodes. Nodal metastases can occur in the form of well-developed papillae, even when the primary tumour in the thyroid gland having predominantly follicular pattern [55, 56]. As in the thyroid gland, the nuclei of
20
metastatic PTC are also more characteristic. Nodal metastases of thyroid carcinoma also tend to go for cystic degeneration, which sometimes can be so extensive, that it may resemble a branchial cleft cyst.
MALIGNANCIES OF FEMALE GENITAL TRACT:
ENDOMETRIAL CARCINOMA
The most common sites of extra uterine spread of endometrial
Adenocarcinoma particularly of endometrioid type are pelvic nodes and para aortic nodes and ovaries. Lymph node metastases can occur in approximately 5%–25% of clinically stage I tumours and in invasive high-grade tumours (even if they are superficial), and also in large sized and/or deeply invasive tumours regardless of their grade, in tumours which extends into cervix, and in tumours having vascular invasion[57, 58]. And serous carcinoma is having a particular propensity for lymph vessel permeation.
CERVICAL CARCINOMA
Cervical carcinoma spreads by direct extension to the vagina, endometrium and myometrial wall, parametria, the lower urinary tract and also to the uterosacral ligaments [59, 60]. Nodal metastases are also common. The pattern of lymph nodes involvement generally proceeds in a sequential fashion.
The first station is represented by the paracervical, obturator, hypogastric and external iliac groups and the second station by sacral, common iliac, aortic, and the inguinal groups[61]. Incidence of nodal involvement is directly related to the stage of the disease.
21 CARCINOMA OF OVARY
The incidence of nodal involvement in case of ovarian cancer reported in the literature is 10.6 –24% for stage I cancer, 23 –50% for stage II cancer, 53 – 74% for stage III cancer, and 65 – 75% for stage IV cancer[62-65]. It has been
reported that lymph node involvement is more commonly seen with serous and clear cell malignancies than with other types [65, 66] and that low-grade malignancies are closely associated with nodal disease. The locations of lymph nodes involvement in ovarian cancer depend on histologic type of the primary malignancy. In case of serous tumour, the para-aortic lymph nodes, particularly above the inferior mesenteric artery are the site for the earliest nodal metastasis.
But, the likelihood of pelvic lymph nodes involvement is almost equal to that of the para-aortic lymph node involvement in cases of non-serous tumour.
CARCINOMA OF ORAL CAVITY
Metastases in case of malignancies of oral cavity occur primarily by lymphatic route, the distribution of lymph nodes involved by tumour depends on the location of the primary tumour[67]. The more anterior the location of primary tumour, the lower the position of the cervical lymph node involvement.
Primary carcinomas of base of the tongue and oropharynx tend to metastasize to upper cervical lymph nodes. These metastases are often cystic and frequently present before the detection of the primary malignancy. Metastases to the lymph nodes of posterior triangle - level V lymph nodes are rare, they found be involved in only about 6% of the oropharyngeal malignancies and 1% of the
22
oral malignancies[68]. Features of the primary carcinomas associated with the likelihood of lymph node metastases are location (higher for the oropharynx and posterior portion of tongue, middle for anterior portion of the tongue, and lower for floor of mouth, lip, buccal mucosa- cheek, gingiva and hard palate), high grade of microscopic differentiation, and depth of invasion[69,70]. Carcinomas of the lip associated with metastases tend to be wide, deep, and have high grade of differentiation, and associated with an inflammatory and desmoplastic response[71]. sometimes, the cervical lymph node metastases from these squamous cell carcinomas undergo cystic degeneration. This, along with the well differentiated nature of lesion, may easily lead to a mistaken diagnosis of branchial cyst with malignant transformation called as “branchial carcinoma”[72]. Another important peculiar morphological feature that
squamous cell carcinoma can exhibit when metastasizing to cervical lymph nodes is that an extensive foreign body giant cell reaction around the clumps of keratin, without the viable malignant cells, this is particularly common if the neoplasm has been irradiated previously [73].
MIMICKERS OF METASTASIS IN LYMPHNODE
Inclusions of various types of benign tissue can also occur within the lymph nodes[74], and these inclusions can also be mistakenly diagnosed as metastasis.
23 These include the following:
1. Salivary gland tissue– It is a common finding in high cervical lymph nodes, and to be regarded as a normal event related to the embryology of this region [75]. Both the ducts and acini are usually present. These inclusions may also undergo neoplastic changes, Warthin tumour is the most common type, but many other types have also been reported, including benign mixed tumour (pleomorphic adenoma), monomorphic adenoma, mucoepidermoid carcinoma, and acinic cell carcinoma.
2. Squamous epithelium - Microscopic cystic structures lined by well differentiated squamous epithelial cells are sometimes seen in the upper cervical lesion. They are thought to represent an anomaly, being composed of branchial pouch derivatives. The term “benign lympho epithelial cyst” is also sometimes applied to these structures. It is hypothesized that these formations are result from cystic dilatation of pre-existing epithelial inclusions as a result of their stimulation by the lymphoid component that surrounds them, a same pathogenesis also applies to multilocular thymic cysts, other cystic structures of the head and neck region, and also to Warthin tumour itself. Similar formations have also been described in peri pancreatic lymph nodes[76]. The obvious differential diagnosis is well differentiated squamous cell carcinoma metastasis, which particularly in the cervical region is notorious for its tendency to undergo marked cystic changes[77].
24
3. Thyroid follicles - They can be found in the capsular or sub capsular region of mid cervical lymph nodes in the absence of any pathologic changes in the thyroid gland. To differentiate it from metastatic thyroid carcinoma can be very difficult.
4. Decidual reaction - During pregnancy the decidual reaction can occur within the pelvic lymph nodes and they may mimic as metastatic carcinoma[78]. The decidual reaction can occur in the stromal cells of endometriosis foci or in hormonally receptive cells of this region, in a manner similar to that seen in peritoneal decidual reaction.
5. Mullerian-type epithelium - Glandular inclusions lined by cuboidal cells with a mullerian or coelomic appearance sometimes found in the capsule of the pelvic lymph nodes of females and sometimes within the lymph node itself [79,80]. Their appearance and the pathogenesis is similar to those of the peritoneal lesions, usually known as endosalpingiosis. These nodal inclusions may be difficult to distinguish from the metastases originating in low-grade ovarian malignancies, as they may grow into the peripheral sinuses, and form papillae, sometimes be accompanied by psammoma bodies, and even proliferate as small sheets of cells[81]. Some authors suggested that some of these inclusions are actually metastases from the ovarian serous borderline tumours[82]. Morphologically similar inclusions have also been seen in the mediastinal lymph nodes of males and axillary lymph nodes of females.
Glandular inclusions of similar appearance but surrounded by endometrial-type
25
stroma in the lymph node occur less frequently and they represent nodal endometriosis.
6. Nevus cells- Clusters of normal-appearing nevus cells occasionally may found in the capsule of lymph nodes, without involvement of the parenchyma of the lymph node. Most of the such reported cases have found to be occurred in the axillary lymph nodes[83]. A related lesion is the blue nevus that has been reported in the capsule of lymph node [84]. The morphologic features of these formations may mimic metastatic malignant melanoma deposits.
7. Mesothelial cells – Rarely mesothelial cells are found within the lymph nodes in the apparent absence of a malignant mesothelioma[28, 85, 86]. The differential diagnosis is with metastatic malignant mesothelioma from an occult primary which may be present in the peritoneal cavity / pleura[17].
8. Breast tissue –Sometimes normal mammary lobules may present within the axillary lymph nodes[87-89]. And slightly more common occurrence in axillary lymph nodes is that presence of tubules lined by a single layer of cuboidal cells, sometimes with a hobnail appearance located in the lymph node capsule or immediately beneath it. These formations are similar to the mullerian-type epithelial inclusions which may occur in the pelvic lymph nodes. Hence some of these cases occur in patients with breast malignancy, it may interfere with the diagnosis of metastatic tumour [90, 91]. Epithelial inclusions which are present in the axillary lymph nodes of females can be classified into three major groups, those composed exclusively of glandular structures, those composed only of
26
squamous cysts, and those containing both glandular and squamous epithelium[92].
ROLE OF CYTOKERATIN IN DETECTING OCCULT METASTASIS Keratins are the main cytoskeletal component of epithelial cells and the most diverse group of intermediate filaments. Fifty-four functional keratin genes have been identified in humans [93]. These genes have been subdivided into 28 type I genes and 26 type II genes that form 2 clusters of 27 genes each on chromosome 17q12-q21 and 12q11-q13, respectively. Keratins have been subdivided into 2 major sequence types corresponding to class I and class II of the current classification of intermediate filaments [94]. Type I is comprised of 17 epithelial and 11 hair keratins, and type II is composed of 20 epithelial and 6 hair keratins . Keratins are resistant to degradation, show great fidelity of expression, and are very antigenic. All keratins have a common structure, which consists of a central alpha-helical rod domain of 310 amino acid residues that is flanked on either side by head and tail domains. The head domain is the amino terminus, while the tail domain is the carboxyl terminus. Specific keratins are expressed in different epithelia. Stratified squamous epithelia express mostly keratins 1 to 6 and 9 to 17, while keratins 7, 8, 18, 19, and 20 are identified in simple epithelia. Of the latter, keratins 8, 18, and 19 are the most abundant in malignancies [95].
Although it was originally believed that keratin expression was restricted to epithelial cells, subsequent studies demonstrated their presence in subsets of
27
several types of mesenchymal cells, including smooth muscle cells of the myometrium and atherosclerotic plaques, virally transformed fibroblasts, and subsets of cultured smooth muscle cells, subserosal connective tissue cells, normal fetal myocardium, vascular endothelial cells, and interstitial reticulum cells of lymphoid tissue [96].
AE1/AE3 is the broad-spectrum keratin antibody cocktail that is probably the most commonly used in surgical pathology. It is composed of the mouse monoclonal antibody AE1 that recognizes the acidic (type I) keratins 10, 14, 15, 16, and 19, and AE3 that reacts with the basic (type II) keratins 1, 2, 3, 4, 5, 6, 7, and 8 [97]. Both clones were generated using epidermal keratin as immunogen. A drawback of this cocktail is that it can cross-react with other intermediate filaments, particularly glial fibrillary acidic protein and, thus, may give a false-positive staining result[98]. Another shortcoming of this cocktail is that it does not react with keratin 18, which is expressed in a wide variety of carcinomas. Therefore, it is important to keep in mind that a negative staining for AE1/ AE3 should not be regarded as sufficient evidence to rule out the possibility of carcinoma. The carcinomas that are most frequently negative for AE1/AE3 are hepatocellular carcinomas [99], adrenal cortical carcinomas [99], some renal cell carcinomas (clear cell and chromophobe) [100], and renal oncocytomas [100, 101]. To increase the sensitivity of the AE1/ AE3 cocktail for detecting epithelial differentiation, some commercial sources have added other clones to this cocktail, such as 5D3, which reacts with keratins 8 and 18.
28
The recognition of epithelial differentiation in well- or moderately differentiated carcinomas does not pose significant diagnostic difficulty on routine histologic preparations since evidence of such differentiation (e.g.
keratinization or glandular formation) is usually apparent. In those instances in which the neoplasm shows little or no evidence of epithelial differentiation, immunohistochemical studies using a variety of broad-spectrum epithelial markers are often necessary to either confirm or rule out the epithelial nature of the tumour[4].
Occult nodal metastases which are not identified by the routinely used method of examining a single haematoxylin and eosin (HE) stained slides per lymph node have been detected for years[102,103], but their prognostic significance is not well established[104]. Therefore, those occult metastases which are missed on routine methods can be identified either by evaluating further deeper sections of the blocks, or by using a more efficient method of detecting malignant cells. IHC can be used for the latter purpose using epithelial markers.
All cytokeratin positive cells should not be considered as metastatic deposits, since some instance, artefactually displaced malignant cells or normal components of nodes (Interstitial reticulum cells) may also show positive with cytokeratin antibodies [105]. And Plasma cells also show positivity with CAM5.2 & Pan ck [106]. Occasionally, cells compatible with histiocyte may also show positivity with cytokeratin. Certainly epithelial inclusions of the
29
lymph nodes also show positivity with cytokeratin[88]. Therefore, morphology should not be neglected with the presence of cytokeratin positivity, which will help to differentiate between the malignant cells and others. So if any doubt exist as to the nature of cytokeratin positive cells, it should not be called as metastases in line with the rules of the TNM staging of malignancies[107].
TNM STAGING OF VARIOUS EPITHELIAL MALIGNANCIES[108]:
DEFINITIONS OF AJCC TNM- BREAST
Definition of Primary Tumour (T) – Clinical and Pathological TX - Primary tumour cannot be assessed
TO - No evidence of primary tumour Tis (DCIS)- Ductal carcinoma in situ
Tis (Paget) - Paget disease of the nipple not associated with invasive carcinoma and/or carcinoma in situ (DCIS) in the underlying parenchyma.
TI - Tumour < 20 mm in greatest dimension
T2 -Tumour > 20 mm but < 50 mm in greatest dimension T3 -Tumour > 50 mm in greatest dimension
T4 -Tumour of any size with direct extension to the chest wall and/or to the skin T4a - Extension to the chest wall
T4b - Ulceration and/or ipsilateral macroscopic satellite nodules and/or edema (including peau d ’orange) of the skin
T4c - Both T4a and T4b are present T4d - Inflammatory carcinoma
30
Definition of Regional Lymph Nodes -Pathological (pN) pNX - Regional lymph nodes cannot be assessed
pNO - No regional lymph node metastasis identified
pN0(i+) - ITCs only (malignant cell clusters no larger than 0.2 mm) pN1- Micro metastases or metastases in 1-3 axillary lymph nodes.
pN2 - Metastases in 4 -9 axillary lymph nodes
pN3 - Metastases in 10 or more axillary lymph nodes Definition of Distant Metastasis (M)
M0 - No clinical or radiographic evidence of distant metastases
MI - Distant metastases detected by clinical and radiographic means and/or histologically proven metastases larger than 0.2 mm (pM)
31 AJCC PROGNOSTIC STAGE GROUPS
T N M STAGE
Tis N0 M0 0
T1 N0 M0 IA
T0 N1mi M0 IB
T1 N1mi M0 IB
T0 N1 M0 IIA
T1 N1 M0 IIA
T2 N0 M0 IIA
T2 N1 M0 IIB
T3 N0 M0 IIB
T0 N2 M0 IIIA
T1 N2 M0 IIIA
T2 N2 M0 IIIA
T3 N1 M0 IIIA
T3 N2 M0 IIIA
T4 N0 M0 IIIB
T4 N1 M0 IIIB
T4 N2 M0 IIIB
Any T N3 M0 IIIC
Any T Any N M1 IV
32
DEFINITIONS OF AJCC TNM -STOMACH Definition of Primary Tumour (T)
TX - Primary tumour cannot be assessed TO - No evidence of primary tumour
Tis - Carcinoma in situ: intraepithelial tumour without invasion of the lamina propria, high-grade dysplasia
TI - Tumour invades the lamina propria, muscularis mucosae, or submucosa T1a - Tumour invades the lamina propria or muscularis mucosae
Tlb - Tumour invades the submucosa
T2 -Tumour invades the muscularis propria
T3 -Tumour penetrates the sub serosal connective tissue without invasion of the visceral peritoneum or adjacent structures
T4 -Tumour invades the serosa (visceral peritoneum) or adjacent structures T4a Tumour invades the serosa (visceral peritoneum)
T4b Tumour invades adjacent structures/organs
Definition of Regional Lymph Node (N)
NX - Regional lymph node(s) cannot be assessed NO -No regional lymph node metastasis
N1 -Metastasis in one or two regional lymph nodes
N2 -Metastasis in three to six regional lymph nodes N3 -Metastasis in seven or more regional lymph nodes
33
N3a -Metastasis in seven to 15 regional lymph nodes N3b -Metastasis in 16 or more regional lymph nodes Definition of Distant Metastasis (M)
M0-No distant metastasis MI -Distant metastasis
AJCC PROGNOSTIC STAGE GROUPS
T N M STAGE
Tis N0 M0 0
T1 N0 M0 IA
T1 N1 M0 IB
T2 N0 M0 IB
T1 N2 M0 IIA
T2 N1 M0 IIA
T3 N0 M0 IIA
T1 N3a M0 IIB
T2 N2 M0 IIB
T3 N1 M0 IIB
T4a N0 M0 IIB
T2 N3a M0 IIIA
T3 N2 M0 IIIA
34
T4a N1 M0 IIIA
T4a N2 M0 IIIA
T4a N0 M0 IIIA
T4b N3b M0 IIIB
T1 N3b M0 IIIB
T2 N3a M0 IIIB
T3 N3a M0 IIIB
T4a N1 M0 IIIB
T4b N2 M0 IIIB
T4b N3b M0 IIIC
T3 N3b M0 IIIC
T4a N3a M0 IIIC
T4b N3b M0 IIIC
Any T Any N M1 IV
35
DEFINITIONS OF AJCC TNM- SMALL INTESTINE Definition of Primary Tumour (T)
TX -Primary tumour cannot be assessed TO -No evidence of primary tumour
Tis -High-grade dysplasia/carcinoma in situ
TI -Tumour invades the lamina propria or submucosa T1a -Tumour invades the lamina propria
T1b -Tumour invades the submucosa
T2 -Tumour invades the muscularis propria
T3 -Tumour invades through the muscularis propria into the subserosa, or extends into nonperitonealized perimuscular tissue (mesentery or retro peritoneum) without serosal penetration
T4 -Tumour perforates the visceral peritoneum or directly invades other organs or structures
Definition of Regional Lymph Node (N) NX -Regional lymph nodes cannot be assessed NO -No regional lymph node metastasis
N1 -Metastasis in one or two regional lymph nodes N2 -Metastasis in three or more regional lymph nodes Definition of Distant Metastasis (M)
M0-No distant metastasis M1 -Distant metastasis present
36 AJCC PROGNOSTIC STAGE GROUPS
T N M STAGE
Tis N0 M0 0
T1-2 N0 M0 I
T3 N0 M0 IIA
T4 N0 M0 IIB
Any T N1 M0 IIIA
Any T N2 M0 IIIB
Any T Any N M1 IV
DEFINITIONS OF AJCC TNM-COLON Definition of Primary Tumour (T)
TX -Primary tumour cannot be assessed TO -No evidence of primary tumour
Tis -Carcinoma in situ, intramucosal carcinoma TI -Tumour invades the submucosa
T2 -Tumour invades the muscularis propria
T3 -Tumour invades through the muscularis propria into pericolorectal tissues T4 -Tumour invades the visceral peritoneum /invades or adheres to adjacent organ or structure
T4a -Tumour invades through the visceral peritoneum
T4b Tumour directly invades or adheres to adjacent organs or structures
37 Definition of Regional Lymph Node (N) NX -Regional lymph nodes cannot be assessed NO -No regional lymph node metastasis
N1 -One to three regional lymph nodes are positive N1a -One regional lymph node is positive
N1b -Two or three regional lymph nodes are positive Nlc -No regional lymph nodes are positive, but there are tumour deposits in the subserosa/mesentery/nonperitonealized pericolic/perirectal/mesorectal tissues.
N2 -Four or more regional nodes are positive N2a -Four to six regional lymph nodes are positive N2b -Seven or more regional lymph nodes are positive Definition of Distant Metastasis (M)
M0-No distant metastasis by imaging, no evidence of tumour in distant sites or organs
M1 -Metastasis to one or more distant sites/organs/peritoneal metastasis is identified
38 AJCC PROGNOSTIC STAGE GROUPS
T N M STAGE
Tis N0 M0 0
T1,T2 N0 M0 I
T3 N0 M0 IIA
T4a N0 M0 IIB
T4b N0 M0 IIC
T1-T2 N1/N1c M0 IIIA
T1 N2a M0 IIIA
T3-T4a N1/N1c M0 IIIB
T2-T3 N2a M0 IIIB
T1-T2 N2b M0 IIIB
T4a N2a M0 IIIC
T3-T4a N2b M0 IIIC
T4b N1-N2 M0 IIIC
Any T Any N M1 IV
39
DEFINITIONS OF AJCC TNM-ORAL CAVITY Definition of Primary Tumour (T)
TX -Primary tumour cannot be assessed Tis -Carcinoma in situ
TI -Tumour< 2 cm, < 5 mm depth of invasion (DOI) T2 -Tumour < 2 cm, DOI > 5 mm and < 1 0 mm or tumour > 2 cm but < 4 cm, and < 10 mm DOI T3 -Tumour>4 cm or any tumour> 10 mm DOI
T4 -Moderately advanced or very advanced local disease T4a -Moderately advanced local disease
Lip-Tumour invades through cortical bone or involves the inferior alveolar nerve, floor of mouth/skin of face.
Oral cavity-Tumour invades adjacent structures only (e.g., through cortical bone of the mandible or maxilla, or involves the maxillary sinus or skin of the face).
T4b -Very advanced local disease Tumor invades masticator space, pterygoid plates, or skull base and/or encases the internal carotid artery
Pathological N (pN)
NX -Regional lymph nodes cannot be assessed NO -No regional lymph node metastasis
NI -Metastasis in a single ipsilateral lymph node 3 cm or smaller and ENE(-) N2 -Metastasis in a single ipsilateral lymph node 3 cm or smaller and ENE(+) or larger than 3 cm but not larger than 6 cm and ENE(-);
40
or metastases in multiple ipsilateral lymph nodes, none larger than 6 cm and ENE(-);
or in bilateral or contralateral lymph nodes,none larger than 6cm and ENE(-) N3 -Metastasis in a lymph node larger than 6cm and ENE(-)
or in a single ipsilateral node larger than 3 cm and ENE(+)
or multiple ipsilateral, contralateral or bilateral nodes any with ENE(+) Definition of Distant Metastasis (M)
M0-No distant metastasis M1 -Distant metastasis
41 AJCC PROGNOSTIC STAGE GROUPS
T N M STAGE
T1 N0 M0 I
T2 N0 M0 II
T3 N0 M0 III
T1,2,3 N1 M0 III
T4a N0,N1 M0 IVA
T1,2,3,4a N2 M0 IVA
Any T N3 M0 IVB
T4b Any N M0 IVB
Any T Any N M1 IVC
DEFINITIONS OF AJCC TNM-ENDOMETRIUM
Definition of Primary Tumour (T) TX - Primary tumour cannot be assessed T0 -No evidence of primary tumour
TI - Tumour confined to the corpus uteri, including endocervical glands T1a - Tumour limited to the endometrium or
invading less than half the myometrium
Tlb - Tumour invading one half or more of the myometrium
T2 - Tumour invading the stromal connective tissue of the cervix but not extending beyond the uterus
42
T3 - Tumour involving serosa, adnexa, vagina/ parametrium T3a -Tumour involving the serosa and/or adnexa
T3b -Vaginal involvement or parametrial involvement
T4 -Tumour invading the bladder mucosa and/or bowel mucosa Definition of Regional Lymph Node (N)
NX -Regional lymph nodes cannot be assessed N0 -No regional lymph node metastasis
N1 -Regional lymph node metastasis to pelvic lymph nodes
N2-Regional lymph node metastasis to para-aortic lymph nodes, with or without positive pelvic lymph nodes
M Category FIGO Stage M Criteria M0-No distant metastasis
MI -Distant metastasis
43 AJCC PROGNOSTIC STAGE GROUPS
T N M STAGE
T1 N0 M0 I
T1a N0 M0 IA
T1b N0 M0 IB
T2 N0 M0 II
T3 N0 M0 III
T3a N0 M0 IIIA
T3b N0 M0 IIIB
T1-T3 N1 M0 IIIC1
T1-T3 N2 M0 IIIC2
T4 Any N M0 IVA
Any T Any N M1 IVB
DEFINITIONS OF AJCC TNM-CERVIX
Definition of Primary Tumour (T) TX - Primary tumour cannot be assessed T0 -No evidence of primary tumour
TI-Cervical carcinoma confined to the uterus
T1a-Invasive carcinoma diagnosed only by microscopy. Stromal invasion with a maximum depth of 5.0 mm measured from the base of the epithelium and a
44 horizontal spread of 7.0 mm or less.
Tlb -Clinically visible lesion confined to the cervix or microscopic lesion greater than Tla. Includes all macroscopically visible lesions, even
those with superficial invasion.
T2 -Cervical carcinoma invading beyond the uterus but not to the pelvic wall or to lower third of the vagina
T2a -Tumour without parametrial invasion T2b -Tumour with parametrial invasion
T3 -Tumour extending to the pelvic side wall and/or involving the lower third of the vagina and/or causing hydronephrosis or nonfunctioning kidney
T4 -Tumour invading the mucosa of the bladder or rectum and/or extending beyond the true pelvis
Definition of Regional Lymph Node (N) NX -Regional lymph nodes cannot be assessed NO -No regional lymph node metastasis
N0(i+) -Isolated tumour cells in regional lymph node(s) no greater than 0.2 mm NI -Regional lymph node metastasis
Definition of Distant Metastasis (M) M0 -No distant metastasis
MI-Distant metastasis
45 AJCC PROGNOSTIC STAGE GROUPS
T N M STAGE
T1 Any N M0 I
T1a Any N M0 IA
T1b Any N M0 IB
T2 Any N M0 II
T2a Any N M0 IIA
T2b Any N M0 IIB
T3 Any N M0 III
T3a Any N M0 IIIA
T3b Any N M0 IIIB
T4 Any N M0 IVA
Any T Any N M1 IVB
DEFINITIONS OF AJCC TNM-OVARY
Definition of Primary Tumour (T) TX -Primary tumour cannot be assessed T0 -No evidence of primary tumour
T1 -Tumour limited to ovaries (one or both)
T1a -Tumour limited to one ovary (capsule intact), no tumour on ovarian surface, no malignant cells in ascites or peritoneal washings
46
T1b -Tumour limited to both ovaries (capsules intact), no tumour on ovarian surface, no malignant cells in ascites or peritoneal washings T1c -Tumour limited to one or both ovaries with any of the following T1c1 -Surgical spill
T1c2 -Capsule ruptured before surgery or tumour on ovarian or fallopian tube surface
T1c -Malignant cells in ascites or peritoneal washings
T2 -Tumour involves one or both ovaries with pelvic extension below pelvic brim
T2a –Extension and/or implants on the uterus and/or tube(s) T2b -Extension to and/or implants on other pelvic tissues
T3 -Tumour involves one or both ovaries with microscopically confirmed peritoneal metastasis outside the pelvis and/or metastasis to the retroperitoneal lymph nodes
T3a -Microscopic extrapelvic (above the pelvic brim) with or without positive retroperitoneal lymph nodes
T3b -Macroscopic peritoneal metastasis beyond pelvis 2 cm or less in greatest dimension with or without metastasis to the retroperitoneal lymph nodes T3c - Macroscopic peritoneal metastasis beyond the pelvis more than2 cm in greatest dimension with or without metastasis to the retroperitoneal
lymph nodes (includes extension to capsule of liver and spleen without parenchymal involvement of either organ)
47 Definition of Regional Lymph Node (N) NX -Regional lymph nodes cannot be assessed N0 -No regional lymph node metastasis
N0(i+) -Isolated tumour cells in regional lymph node(s) no greater than 0.2 mm N1 -Positive retroperitoneal lymph nodes only (histologically confirmed)
N1a -Metastasis up to 10 mm in greatest dimension N1b -Metastasis more than 10 mm in greatest dimension Definition of Distant Metastasis (M)
M0-No distant metastasis
M1 -Distant metastasis including pleural effusion with positive cytology(M1a) liver or splenic parenchymal metastasis, metastasis to extra-abdominal
organs (including inguinal lymphnodes and lymph nodes outside the abdominal cavity ): and transmural involvement of intestine(M1b)
48 AJCC PROGNOSTIC STAGE GROUPS
T N M STAGE
T1 N0 M0 I
T1a N0 M0 IA
T1 N0 M0 IB
T1 N0 M0 IC
T2 N0 M0 II
T2 N0 M0 IIA
T2 N0 M0 IIB
T1/T2 N1 M0 IIIA1
T3 N0/N1 M0 IIIA2
T3 N0/N1 M0 IIIB
T3 N0/N1 M0 IIIC
Any T Any N M1 IV
Any T Any N M1a IVA
Any T Any N M1b IVB
DEFINITIONS OF AJCC TNM-THYROID
Definition of Primary Tumour (T)
TX -Primary tumour cannot be assessed TO -No evidence of primary tumour
49 TI -Tumour <2 cm limited to the thyroid
T2 -Tumour >2 cm but <4 cm limited to the thyroid
T3 -Tumour >4 cm limited to the thyroid(T3a), or gross extra thyroidal extension invading only strap muscles(T3b)
T4 -Includes gross extra thyroidal extension
T4a -Gross extra thyroidal extension invading subcutaneous soft tissues, larynx, trachea, esophagus, or recurrent laryngeal nerve
T4b -Gross extra thyroidal extension invading prevertebral fascia or encasing the carotid artery or mediastinal vessels.
Definition of Regional Lymph Node (N) NX -Regional lymph nodes cannot be assessed
N0-No evidence of loco regional lymph node metastasis N1 -Metastasis to regional nodes
N1a-Metastasis to level VI or VII lymph nodes. This can be unilateral/bilateral N1b -Metastasis to levels I. II. III. IV, or V.This unilateral, bilateral, or
contralateral lateral neck lymph nodes or retropharyngeal lymph nodes Definition of Distant Metastasis (M)
M0 -No distant metastasis M1 -Distant metastasis
50 AJCC PROGNOSTIC STAGE GROUPS
AGE(Years) T N M STAGE
<55 Any T Any N M0 I
<55 Any T Any N M0 II
≥55 T1 N0/NX M0 I
≥55 T1 N1 M0 II
≥55 T2 N0/NX M0 I
≥55 T2 N1 M0 II
≥55 T3a/T3b Any N M0 II
≥55 T4a Any N M0 III
≥55 T4b Any N M0 IVA
≥55 Any T Any N M1 IVB
DEFINITIONS OF AJCC TNM-BLADDER
Definition of Primary Tumour (T)
TX -Primary tumour cannot be assessed T0-No evidence of primary tumour Ta -Non-invasive papillary carcinoma
Tis -Urothelial carcinoma in situ:"fiat tumour”
TI -Tumour invades lamina propria (subepithelial connective tissue) T2 -Tumour invades muscularis propria
51
pT2a -Tumour invades superficial muscularis propria (inner half) pT2b -Tumour invades deep muscularis propria (outer half) T3 -Tumour invades perivesical soft tissue
pT3a -Microscopically
pT3b -Macroscopically (extravesical mass)
T4 -Extravesical tumor directly invades any of the following: prostatic stroma.
seminal vesicles, uterus. vagina, pelvic wall. abdominal wall
T4a -Extravesical tumor invades directly into prostaticstroma. uterus, vagina T4b -Extravesical tumor invades pelvic wall, abdominal wall
Definition of Regional Lymph Node (N) NX -Lymph nodes cannot be assessed N0-No lymph node metastasis
N1 -Single regional lymph node metastasis in the true pelvis (perivesical, obturator. internal and external iliac, or sacral lymph node)
N2 -Multiple regional lymph node metastasis in the true pelvis N3 Lymph node metastasis to the common iliac lymph nodes Definition of Distant Metastasis (M)
M0-No distant metastasis M1 -Distant metastasis
M1a -Distant metastasis limited to lymph nodes beyond the common iliacs MIb -Non-lymph-node distant metastases
52 AJCC PROGNOSTIC STAGE GROUPS
T N M STAGE
Ta N0 M0 0a
Tis N0 M0 0is
T1 N0 M0 I
T2a N0 M0 II
T2b N0 M0 II
T3a,T3b,T4a N0 M0 IIIA
T1-T4a N1 M0 IIIA
T1-T4a N2,N3 M0 IIIB
T4b N0 M0 IVA
Any T Any N M1a IVA
Any T Any N M1b IVB
