Transitional cell carcinomas of the ovary and bladder are immunophenotypically different

Molecular Histopathology for Establishing Diagnostic Method and Clinical Therapy for Ovarian Carcinoma

Ovarian carcinoma (OC) is considered the deadliest gynecological malignancy. It is typically diagnosed in the advanced stages of the disease, with metastatic sites widely disseminated within the abdominal cavity. OC treatment is challenging due to the high rate of disease recurrence, which is further complicated by acquired chemoresistance caused by the reversion of the pathological variant. Therefore, more effective treatments are still being sought. Histologically, OC is classified into serous, mucinous, endometrioid, clear cell, and transitional cell carcinomas and malignant Brenner tumor. Recent clinicopathological and molecular biological studies demonstrated that these subtypes differ in histogenesis and anti-tumor agent sensitivity. In Japan, the incidence rates of the histological types of OC, namely, serous carcinoma, mucinous carcinoma, endometrioid carcinoma, and clear cell adenocarcinoma, are 39%, 12%, 16%, and 23%, respectively. Serous carcinoma is classified as high or low grade, with the former accounting for the overwhelming majority. In this study, the molecular pathological classification of OC has been described based on the characteristics of the two types of OC, types 1 and 2. Compared with Europe and the United States, Japan has a higher prevalence of type 1 OC and a lower prevalence of type 2 OC. The prevalence of each type of OC varies by race. It has been elucidated that the prevalence rate of each type of ovarian cancer in Asian countries is similar to that in Japan. Thus, OC is a heterogeneous disease. Furthermore, OC has been attributed to molecular biological mechanisms that vary among tissue subtypes. Therefore, it is necessary to conduct treatment based on accurate diagnoses of each tissue type and establish an optimal treatment strategy, and now is the transition period.

Transitional cell carcinoma of the ovary: case series and review of literature

Transitional cell carcinoma (TCC) of the ovary is a recently recognized, subtype of ovarian surface epithelial cancer; the pure form accounting for only 1% of surface epithelial tumors. It has been described as a primary ovarian carcinoma with definite urothelial features but no benign, metaplastic and/or proliferating Brenner tumor (BT) identified. Recognition of such tumours is important because of its rarity, favorable response to chemotherapy and an improved patient survival. A case series of primary TCC of the ovary (3 cases) with brief review of literature is being presented.

Value of GATA3 immunostaining in tumor diagnosis: a review

GATA3 is a member of a group of zinc-finger transcription factors that is involved in cell development and differentiation. Recent studies have shown that, among tumors, GATA3 is commonly expressed in both urothelial tumors and breast epithelial neoplasms. With the exception of salivary gland and parathyroid tumors, GATA3 has been reported to be either absent or only rarely expressed in other epithelial tumors. Owing to its restricted expression in urothelial and breast carcinomas, GATA3 has proved to be a useful immunohistochemical marker for assisting in distinguishing these 2 groups of neoplasms from other malignancies with which they may be confused.

Urothelial carcinoma in both adnexa following perforation during transurethral resection of a non-muscle-invasive bladder tumor: a case report and literature review

In this article case report of urothelial carcinoma implantation in both adnexa is reported, following a perforation of the bladder wall during a transurethral resection of a bladder tumor. The 81-year-old female patient had an extensive history of multiple recurrent non-muscle-invasive urothelial carcinoma of the bladder. Intraperitoneal perforation was detected and managed conservatively. Fifteen months after the procedure, the patient presented at the gynecology department with a mass in the left adnex, which was suspicious for malignancy, for which she subsequently underwent hysterectomy in combination with bilateral resection of the adnexa. Pathology showed papillary urothelial carcinoma in both ovaries. A literature search was performed to present an up-to-date review of the available data on bladder perforations during transurethral resection of the bladder and tumor implantation, its management and oncological outcomes.

Metastatic Neoplasms Involving the Ovary

In this review, ovarian metastatic carcinomas from various sites, as well as other neoplasms secondarily involving the ovary, are discussed. As well as describing the morphology, the value of immunohistochemistry in distinguishing between primary and metastatic neoplasms in the ovary is discussed. While immunohistochemistry has a valuable role to play and is paramount in some cases, the results should be interpreted with caution and with regard to the clinical picture and gross and microscopic pathologic findings.

Nonserous Ovarian Epithelial Tumors

This review covers the group of relatively uncommon nonserous ovarian epithelial tumors. The authors focus on the group's distinctiveness from the much more common serous tumors and show the similarities across entities. Diagnostic criteria that separate the different entities are currently being debated. Particular problems include the reproducible diagnosis of high-grade endometrioid, transitional cell, mixed epithelial and undifferentiated carcinomas. Furthermore, despite recognition that most malignant mucinous tumors involving ovary represent metastases from extraovarian primary sites, many misdiagnoses still occur. The authors discuss their rationale behind their opinions about these problematic topics.

Ovarian carcinoma pathology and genetics: recent advances

In this review we summarize recent advances in the histopathological diagnostic criteria and molecular pathology of the main subtypes of ovarian surface epithelial carcinoma. These advances have greatly improved our understanding of the biology of ovarian carcinoma and are also relevant to patient management. With progress toward subtype-specific treatment of ovarian carcinoma, accurate, reproducible histopathological diagnosis of these subtypes by practicing pathologists is increasingly important.

Problems arising in the diagnosis of primary ovarian transitional cell carcinoma after the occurrence of a transitional cell carcinoma of the bladder: a report of a difficult case and a critical review of literature

Transitional cell carcinoma (TCC) of the ovary is a recently recognized subtype of ovarian surface epithelial-stromal cancer that morphologically resembles a TCC of the bladder. The most frequent metastases to ovaries come from the gastrointestinal tract and from breast carcinoma, but metastatic TCCs from the urinary tract to the ovary have been reported. TCC of the bladder is the sixth most common cancer in European and North American countries and its incidence has been increasing. We recently observed a woman, who previously had undergone endoscopic resection of a TCC of the bladder. She was affected by an ovarian bilateral tumor with features of malignant transitional cell tumor, characterized by papillae with multilayered transitional epithelium infiltrating the ovarian stroma. In this study, we showed the utility of WT1 and a panel of immunohistochemical markers in the difficult differential diagnosis between bladder and ovarian TCC.

Histological grading in a large series of advanced stage ovarian carcinomas by three widely used grading systems: consistent lack of prognostic significance. A translational research subprotocol of a prospective randomized phase III study (AGO-OVAR 3 protocol)

While there is no doubt that histologic grading is applicable in early stage ovarian carcinoma, it is still in controversial discussion concerning advanced stage ovarian carcinoma. It was the aim of this study to assess the three most widely used grading systems for ovarian carcinoma in terms of prognostic significance, concordance rates, and reproducibility in a large number of advanced stage ovarian carcinomas of all types after standardized chemotherapy. Representative hematoxylin and eosin slides from 334 cases of stage IIB-IV ovarian carcinoma (prospective randomized, multi-center, phase III study) were used. The first round was grading of all cases according to FIGO, GOG, and Silverberg by one author. The second round (after 1 year) was 30 randomly selected cases graded by three authors. None of the three grading systems was prognostically significant (FIGO p = 0.38; GOG p = 0.70; Silverberg p = 0.92). The concordance rates between the three systems were as follows: FIGO/GOG 95.5%, kappa = 0.929; Silverberg/FIGO 69.9%, kappa = 0.533; Silverberg/GOG 66.8%, kappa = 0,481. Grading of advanced stage ovarian carcinomas was of no value for estimation of prognosis in this homogeneously treated patient group. Alternative methods should be defined, which might help to separate patients with high risk of tumor progression from others with low risk.

p63 expression in ovarian tumours: a marker for Brenner tumours but not transitional cell carcinomas

AIMS

To investigate p63 expression in ovarian neoplasms.

METHODS AND RESULTS

Immunohistochemistry using an antibody that detects all p63 isoforms was performed on 103 primary ovarian neoplasms of different histological types. Diffuse nuclear immunoreactivity of p63 was demonstrated in the 17 benign and five borderline Brenner tumours. Only one of the six malignant Brenner tumours displayed p63 expression. p63 immunoreactivity was absent in all the ovarian transitional cell carcinomas (TCC), but was demonstrated extensively in TCCs of the urinary bladder. Besides focal p63 expression in epidermal basal cells of immature and mature teratomas, all other ovarian lesions were devoid of p63 expression. p63 expression was also demonstrated in cervical transitional cell metaplasia and Walthard cell nests of fallopian tubes.

CONCLUSIONS

Expression of p63 protein is apparently cell lineage specific and in ovarian neoplasms is confined to benign and borderline Brenner tumours. The loss of expression in malignant Benner tumours suggests a role for p63 in Brenner carcinogenesis. The distinct patterns of p63 expression in TCCs in the ovary and urinary bladder may help in their differential diagnosis.

Das transitionalzellige Ovarialkarzinom

Transitional cell carcinoma of the ovary (TCC-O) is a less common type of malignant surface epithelial-stromal tumor of the ovary, still with uncertain incidence. Histologically, TCC-O resembles urothelial carcinoma of the urinary system, and by definition does not contain a Brenner tumor component. TCC-O may not be a bona fide urothelial neoplasm, however, but rather a lesion of the Müllerian type derived from the ovarian surface epithelium. This notion is supported by the existence of mixed tumors consisting of TCC-O and other histological types of ovarian carcinoma, as well as the observation that TCC-O has a Müllerian type but not a urothelial-like immunohistochemical profile. Besides metastatic urothelial carcinoma of the urinary tract, the other types of ovarian carcinoma, as well as sex cord-stromal tumors such as adult granulosa cell tumors, have to be considered in the differential diagnosis of TCC-O. A recent analysis of a large series of advanced ovarian carcinomas treated by radical surgery and postoperative chemotherapy confirms studies that had suggested that TCC-O has a better prognosis (with current treatment) than that of the other histological types of ovarian carcinoma. Further studies applying standardized histopathological criteria are needed to clarify the true incidence and behavior of TCC-O. In addition, it is important to study the biological and molecular background of this apparently less aggressive phenotype.

Herpetiform cutaneous metastases from transitional cell carcinoma of the urinary bladder: immunohistochemical analysis

The case of an 83-year-old woman with an uncommon presentation of cutaneous metastases from muscle-invasive transitional cell carcinoma of the urinary bladder is reported. The band-like eruption of the metastatic lesion can often be misdiagnosed and treated initially as herpes zoster. A detailed immunohistochemical analysis is also described to differentiate metastatic lesions from other sources.

Immunohistochemistry as a diagnostic aid in the evaluation of ovarian tumors

Aspects of immunohistochemistry (IHC), which are useful in the diagnosis of ovarian tumors (mostly neoplasms but also a few tumor-like lesions), are discussed. The topic is first approached by considering the different growth patterns and cell types that may be encountered. Then a few other specific situations in which IHC may assist are reviewed. Selected findings largely, or only, of academic interest are also mentioned. One of the most common situations in which IHC may aid is in the evaluation of tumors with follicles or other patterns which bring a sex cord-stromal tumor into the differential. The distinction between a sex cord tumor and an endometrioid carcinoma with sex-cord-like patterns may be greatly aided by the triad of epithelial membrane antigen (EMA), inhibin, and calretinin, the latter two being typically positive and EMA negative in sex cord tumors, the converse being typical of endometrioid carcinoma. It should be emphasized that granulosa cell tumors may be inhibin negative and, albeit less specific, calretinin is more reliable in evaluating this particular issue. Lack of staining for inhibin and calretinin may also be supportive in leading to consideration of diverse other neoplasms that may form follicles, including metastatic tumors as varied as carcinoid and melanoma. The well-known staining of the latter neoplasm for S-100 protein and HMB-45 may be very helpful in evaluating melanomas with follicular or other unusual patterns, a challenging aspect of ovarian tumor interpretation. The most common monodermal teratoma, struma ovarii, usually has an overt follicular pattern and is easily recognized, but recognition of unusual appearances ranging from oxyphilic to clear cell to various patterns of malignant struma may be greatly aided by a thyroglobulin or TTF 1 stain. IHC for neuroendocrine markers may assist in the diagnosis of primary and metastatic carcinoid tumor. The broad differential diagnosis of glandular neoplasms with an endometrioid-pseudoendometrioid morphology, or mucinous cell type, has been the subject of much exploration in recent years, particularly the distinction between primary and metastatic neoplasms. The well-known CK7 positive, CK20 negative phenotype of primary endometrioid carcinoma, and the converse profile in most metastatic large intestinal adenocarcinomas with a pseudoendometrioid morphology, has been much publicized but albeit an appropriate supportive adjunct in many cases, exceptions from the typical staining pattern may be encountered. It is even less helpful in the case of primary versus metastatic mucinous neoplasia. Evaluation of the expression of mucin gene products has shown mixed, essentially unreliable, results. Experience with other new markers, such as CDX-2, villin, beta catenin, and P504S (racemase), is limited but is in aggregate promising with regard to providing some aid in this area. The rare differential of metastatic cervical adenocarcinoma versus primary ovarian mucinous or endometrioid carcinoma may be aided by strong p16 staining of the former. Staining for alpha-fetoprotein may aid in confirming the diagnosis of endometrioid-like (and hepatoid) variants of yolk sac tumor. Ependymoma of the ovary may also have an endometrioid-like glandular pattern, but positive stains for glial fibrillary acidic protein contrast with the negative results in others neoplasms with a similar pattern. Immunostains may be very helpful in the evaluation of oxyphilic tumors and tumor-like lesions and in some unusual forms of clear cell neoplasia, such as clear cell struma, both subjects being reviewed herein. Immunostains may highlight both the presence and extent of epithelial cells in a variety of circumstances, including microinvasive foci in cases of serous borderline tumors and mucinous carcinomas, and in determining the extent of carcinoma cells and reactive cells within mural nodules of mucinous neoplasms. As in tumor pathology in general, various markers may be crucial in the diagnosis of small round cell tumors of the ovary, and familiar markers of epithelial, lymphoid, leukemic, and melanocytic neoplasms may assist in the analysis of high grade tumors with a poorly differentiated carcinoma, lymphoma-granulocytic sarcoma, malignant melanoma differential. The evaluation of ovarian cystic lesions may be aided by thyroglobulin or TTF 1 (cystic struma), glial fibrillary acid protein (ependymal cysts), and inhibin-calretinin (follicle cysts and unilocular granulosa cell tumors). Stains for trophoblast markers may occasionally aid in the evaluation of germ cell tumors, although routine stains should usually suffice; they may be of academic interest in confirming trophoblastic differentiation in some high grade surface epithelial carcinomas.

Metastatic neoplasms involving the ovary: a review with an emphasis on morphological and immunohistochemical features

The ovary is a common site of metastatic tumour. In many cases of ovarian metastasis there is a known history of malignancy but in other cases the ovarian tumour is the first manifestation of disease. In this review metastatic colorectal, appendiceal, gastric, breast, pancreatic and biliary tract, hepatocellular, renal, transitional and cervical carcinomas and metastatic malignant melanoma involving the ovary are discussed, as is the issue of synchronous ovarian and endometrial carcinomas. Peritoneal tumours, including primary peritoneal carcinoma, mesothelioma and intra-abdominal desmoplastic small round cell tumour, involving the ovary are also discussed, together with a variety of other rare, metastatic ovarian neoplasms. Many metastatic adenocarcinomas involving the ovary, especially those exhibiting mucinous differentiation, closely mimic primary ovarian adenocarcinomas with morphologically bland areas simulating benign and borderline cystadenoma. This is referred to as a maturation phenomenon. In recent years immunohistochemistry, especially but not exclusively differential cytokeratin (CK7 and CK20) staining, has been widely used as an aid to distinguish between a primary and secondary ovarian adenocarcinoma. While immunohistochemistry undoubtedly has a valuable role to play and is paramount in diagnosis in some cases, the results must be interepreted with caution, especially in mucinous tumours, and within the relevant clinical context. We feel the significance of differential cytokeratin staining is not always understood by histopathologists and this can result in erroneous interpretation. We critically discuss the value of immunohistochemistry and associated pitfalls with each tumour type described.

Diagnostic utility of immunohistochemistry in morphologically difficult prostate cancer: review of current literature

Varma M & Jasani B (2005) Histopathology47, 1-16 Diagnostic utility of immunohistochemistry in morphologically difficult prostate cancer: review of current literatureImmunohistochemistry is widely used to distinguish prostate cancer from benign mimics and to establish the prostatic origin of poorly differentiated carcinoma. We critically review the recent advances in prostate cancer immunohistochemistry, including the introduction of newer basal cell markers such as p63 and the discovery of the overexpression of alpha-methylacyl coenzyme A racemase (AMACR) in prostate cancer. The description of newer urothelial markers to aid the distinction of prostate cancer from urothelial carcinoma is also presented together with refinements in the quality control of PSA and PSAP immunostaining. Although AMACR is a useful immunohistochemical marker for prostate cancer, it has significant limitations. These limitations are discussed and the need for interpreting AMACR immunoreactivity in the appropriate morphological context and in conjunction with basal call markers is emphasized. We also describe the utility of an immunohistochemical panel composed of PSA, PSAP and high molecular weight cytokeratin for distinguishing poorly differentiated prostate cancer from high-grade urothelial carcinoma. A morphological differential diagnosis based selection of immunohistochemical markers is highlighted as a novel approach in the diagnosis of prostate cancer in routine surgical pathology practice.

Survival benefit for patients with advanced-stage transitional cell carcinomas vs. other subtypes of ovarian carcinoma after chemotherapy with platinum and paclitaxel

OBJECTIVE

Transitional cell carcinoma (TCC) of the ovary is a less well recognized histological type of ovarian carcinoma resembling TCC of the urinary bladder. A better prognosis due to a better chemosensitivity of ovarian TCC has been suggested. It was the aim of the present retrospective study to compare incidence and outcome of patients with TCCs and other subtypes of ovarian carcinoma from a large homogeneous collective of patients with primary advanced-stage ovarian carcinoma.

METHODS

H and E-stained sections from a total of 302 cases from a prospective randomized, multi-center, phase III study of patients with ovarian cancer, FIGO-stages IIB-IV, comparing cisplatin plus paclitaxel (PT) with paclitaxel plus carboplatin (TC) were available for histological retyping of ovarian carcinomas applying current WHO criteria. Kaplan-Meier survival analysis was performed.

RESULTS

16 of 302 tumors (5.3%) were diagnosed as TCC. Only 1 of the 16 TCCs had been previously diagnosed as such by referring pathologists. TCCs were associated with smaller preoperative extraovarian tumor and with smaller postoperative residual tumor. 5-year survival of patients with TCC was 57% as compared to 31% for patients with ovarian carcinomas of other types (P = 0.03).

CONCLUSION

TCC of the ovary seems to be a less well recognized entity. In the current series, TCCs had a significantly better prognosis as compared to all other types of ovarian carcinomas after standardized chemotherapy. A propensity for micronodular rather than macronodular extraovarian spread and better surgical resectability of TCC might contribute to the survival benefit.

Ovarian carcinomas, including secondary tumors: diagnostically challenging areas

The differential diagnosis of ovarian carcinomas, including secondary tumors, remains a challenging task. Mucinous carcinomas of the ovary are rare and can be easily confused with metastatic mucinous carcinomas that may present clinically as a primary ovarian tumor. Most of these originate in the gastrointestinal tract and pancreas. International Federation of Gynecology and Obstetrics (FIGO) stage is the single most important prognostic factor, and stage I carcinomas have an excellent prognosis; FIGO stage is largely related to the histologic features of the ovarian tumors. Infiltrative stromal invasion proved to be biologically more aggressive than expansile invasion. Metastatic colon cancer is frequent and often simulates ovarian endometrioid adenocarcinoma. Although immunostains for cytokeratins 7 and 20 can be helpful in the differential diagnosis, they should always be interpreted in the light of all clinical information. Occasionally, endometrioid carcinomas may exhibit a microglandular pattern simulating sex cord-stromal tumors. However, typical endometrioid glands, squamous differentiation, or an adenofibroma component are each present in 75% of these tumors whereas immunostains for calretinin and alpha-inhibin are negative. Endometrioid carcinoma of the ovary is associated in 15-20% of the cases with carcinoma of the endometrium. Most of these tumors have a favorable outcome and they most likely represent independent primary carcinomas arising as a result of a Mullerian field effect. Although the criteria for distinguishing metastatic from independent primary carcinomas rely mainly upon conventional clinicopathologic findings, loss of heterozygosity and gene mutation analyses can be helpful. Transitional cell carcinomas are distinguished from undifferentiated carcinomas by the presence of thick, undulating papillae with smooth luminal borders, microspaces, and tumor cells with distinctive 'urothelial' appearance. Krukenberg tumors are metastatic adenocarcinomas traditionally perceived as composed of mucin-filled signet-ring cells associated with a striking proliferation of the ovarian stroma but many variations on this pattern occur.

Bladder cancer discovered by ovarian metastasis: Cytokeratin expression is useful when making differential diagnosis

A 49-year-old woman underwent hysterectomy and bilateral adnexectomy after the diagnosis of a right ovarian tumor with paraaortic and pelvic lymph node metastases. The pathological diagnosis was undifferentiated carcinoma of the ovary. After the operation, a bladder tumor was discovered during the evaluation for microscopic hematuria. The bladder tumor was pathologically diagnosed as transitional cell carcinoma, pT1b, G3. Although the pathological findings of the bladder cancer and ovarian cancer were very similar, we could diagnose primary bladder cancer with ovary and lymph node metastases according to the immunohistochemical staining pattern of cytokeratins 7 and 20. Herein, the clinical usefulness of immunohistochemical staining using cytokeratins for making a differential diagnosis of the origin of a tumor in the pelvic cavity is demonstrated.

The histologic type and stage distribution of ovarian carcinomas of surface epithelial origin

Advances over the past decade suggest a need to reassess the distribution of ovarian surface epithelial tumors. A series of 220 consecutive invasive ovarian carcinomas, including carcinosarcomas and peritoneal carcinomas, was reviewed. Notable findings include: 7% of tumors were carcinosarcomas; 22% of cases of peritoneal serous carcinomatosis were of peritoneal origin; <3% of cases were mucinous carcinomas; and only one malignant Brenner tumor (0.5%) and no pure transitional cell carcinomas were identified. If peritoneal carcinomas, carcinosarcomas, and mixed carcinomas with a serous component are combined with serous carcinomas, this group accounts for 78% of all cases and 87% of advanced stage cases, suggesting a greater uniformity to epithelial ovarian cancer than previously appreciated.

Transitional Cell Carcinoma of the Ovary

Transitional cell carcinoma (TCC) of the ovary is a recently recognized subtype of ovarian surface epithelial-stromal cancer, and studies of its morphology are few. As a result, the criteria for its diagnosis and spectrum of its morphology are not clearly established. One hundred consecutive consultation cases of ovarian carcinoma with a pure or partial transitional cell pattern (excluding malignant Brenner tumor) diagnosed between 1989 and 2001 were evaluated for the frequency of various pathologic features and the relation of TCC to other surface epithelial-stromal carcinomas. The women were 33 to 94 years of age (mean, 56 years). A total of 47 tumors were stage I, 21 stage II, 31 stage III, and 1 stage IV; 13% of the stage I tumors and 41% of tumors of all stages were bilateral. The tumors ranged from 3.0 to 30 cm in greatest dimension (mean, 10 cm); 60% of them were solid and cystic, 24% solid, and 16% cystic. TCC was the exclusive or predominant component in 93% of the tumors and showed undulating (93%), diffuse (57%), insular (55%), and trabecular (43%) patterns. In four tumors with an insular growth, the pattern focally mimicked a Brenner tumor. Necrosis was present in 57% of the cases. Features that were seen in the tumors that in aggregate produced a relatively consistent appearance were "punched out" microspaces (87%), often the size of Call-Exner bodies, large cystic spaces (73%), and large blunt papillae (63%). Features that were sometimes seen, usually as a focal finding, included slit-like fenestrations (49%), bizarre giant cells (35%), small filiform papillae (18%), gland-like tubules (17%), squamous differentiation (13%), and psammoma bodies (4%). In 23 cases, TCC was a component of a mixed epithelial carcinoma, the additional components being serous adenocarcinoma in 16, endometrioid in 5, mucinous in 1, and clear cell carcinoma in 1. The tumor cells of the TCC component often were relatively monomorphic; 6% of the tumors were grade 1, 43% grade 2, and 51% grade 3. The nuclei were oblong or round and often had large single nucleoli (69%) or longitudinal grooves (48%). The cytoplasm was typically pale and granular but was rarely strikingly clear or oxyphilic. TCC of the ovary usually occurs in pure form but is also common as a component of a surface epithelial carcinoma of mixed cell type. In either situation, TCC has a constellation of architectural and cytologic features that readily distinguish it in most cases from other types of ovarian cancer. Recognition of these features will lead to a more consistent diagnosis of this tumor and aid in determining whether it has distinctive clinical features, particularly with regard to its behavior.

Application of mesothelin immunostaining in tumor diagnosis

Mesothelin is a differentiation antigen that was first described as the antigenic target of the monoclonal antibody K1. Using this antibody, it was demonstrated that mesothelin is strongly expressed in normal mesothelial cells, mesotheliomas, nonmucinous ovarian carcinomas, and some other malignancies. Immunostaining with the K1 antibody was suggested to be useful in the diagnosis of mesothelioma in the early 1990s. This, however, could not be further explored until recently because of the lack of commercially available anti-mesothelin antibodies. In a recent investigation by this author, all epithelioid mesotheliomas and about 40% of the lung adenocarcinomas reacted with the 5B2 anti-mesothelin antibody, which has only recently become commercially available. It was concluded that immunostaining with this antibody has limited value in discriminating between these conditions. The aim of the current study was to further investigate the potential application of the 5B2 antibody in tumor diagnosis. Mesothelin expression was evaluated in formalin-fixed, paraffin-embedded samples of normal tissues and in 471 tumors of various origins. The carcinomas that most frequently exhibited strong mesothelin reactivity were nonmucinous carcinomas of the ovary (14 of 14 serous, 3 of 3 endometrioid, 6 of 8 clear cell, and 4 of 4 transitional cell carcinoma), and adenocarcinomas of the pancreas (12 of 14), the ampulla of Vater (3 of 3), endometrium (7 of 11), lung (14 of 34), and liver (7 of 19 cholangiocarcinomas). The carcinomas that did not express mesothelin included renal cell carcinomas, hepatomas, carcinomas of the thyroid, adrenal cortical carcinomas, prostatic adenocarcinomas, and carcinoid tumors. All germ cell tumors, with the exception of teratomas, were consistently negative for mesothelin. Because of the strong mesothelin expression in nonmucinous carcinomas of the ovary, but not in a variety of tumors with which these lesions may be confused (eg, clear cell carcinoma of the ovary versus endodermal sinus tumor or renal cell carcinoma, clear cell type; transitional cell carcinoma of the ovary versus TCC of the urinary tract), immunostaining for this marker could be useful in establishing the differential diagnosis. The strong mesothelin expression in the large majority of pancreatic ductal adenocarcinomas (12 of 14), but not in normal pancreas, confirms that this marker may have some diagnostic utility in discriminating between neoplastic and nonneoplastic pancreatic ductal epithelium. The mesothelin expression in about one-third of the cholangiocarcinomas, but not in hepatomas, suggests that this marker may have some utility in distinguishing between these two malignancies when they are poorly differentiated. In the group of small round blue cell tumors, only desmoplastic small round cell tumors exhibited mesothelin positivity (7 of 12). Of the soft tissue tumors, only the epithelial component of biphasic synovial sarcomas (9 of 9) expressed mesothelin. These findings indicate that, in some instances, mesothelin immunostaining can assist in the diagnosis of these tumors. Finally, the strong mesothelin reactivity seen in the adenomatoid tumors (3 of 3) provides further support for a mesothelial derivation for this lesion.

Immunoprofile of Ovarian Tumors With Putative Transitional Cell (Urothelial) Differentiation Using Novel Urothelial Markers

Ovarian tumors containing cells with transitional cell morphology are recognized in the 1999 World Health Organization classification of ovarian tumors and include benign Brenner tumor, borderline and malignant Brenner tumor, and transitional cell carcinoma. Recent immunohistochemical investigations have reached conflicting conclusions regarding true urothelial differentiation in ovarian Brenner tumors. We evaluated a panel consisting of antibodies to uroplakin III (UROIII), thrombomodulin (THR), cytokeratin 7 (CK7), cytokeratin 20 (CK20), and Wilms' tumor protein (WT1) to study urothelial differentiation in ovarian transitional cell tumors. Additionally, we compared the immunohistochemical profile of transitional cell carcinoma of the ovary (TCC-O) with that of transitional cell carcinoma of the bladder (TCC-B), to ascertain if immunohistochemistry may aid in distinguishing primary from metastatic TCC-O. Seventeen benign Brenner tumors and 17 TCC-O were stained with antibodies to UROIII, THR, CK7, CK20, and WT1. Additionally, 6 Brenner tumors of borderline malignancy were stained with antibodies to UROIII, THR, CK7, and CK20. The immunohistochemical results were compared with those of 30 cases of noninvasive TCC-B (low malignant potential n=14, low grade n=16) and 36 cases of invasive TCC-B stained with a similar panel of antibodies as part of another study. Twenty-one nontransitional cell ovarian carcinomas (9 serous, 4 clear cell, 5 endometrioid, 2 mixed endometrioid/serous, and 1 mucinous) were used as controls. Most Brenner tumors showed positivity with UROIII (82%) and THR (76%), supporting true urothelial differentiation in these tumors. Although TCC-O has considerable morphologic overlap with TCC-B, they had only partial immunophenotypic overlap. TCC-O rarely expressed UROIII (6%) and THR (18%) and none expressed CK20. In contrast, nearly 40% of invasive TCC-B expressed UROIII, 61% expressed THR, and 50% expressed CK20. Nearly 82% of TCC-O expressed WT1, which was negative in all TCC-B. Our results may have diagnostic value in distinguishing TCC-O (CK20-, UROIII-/+, WT1+) and invasive TCC-B (CK20+, UROIII+/-, WT1-) metastatic to the ovary. They also indicate that the morphologic similarity between TCC-O and TCC-B does not indicate any histogenic similarity and, as others have noted, TCC-O is a variant morphology in the spectrum of surface epithelial carcinomas.

Pathology of ovarian carcinoma

Serous carcinoma is the most common type of ovarian cancer and usually is associated with peritoneal metastases and poor survival except for meticulously staged patients with tumors confined to the ovaries. Endometrioid and clear cell carcinomas account for most nonserous carcinomas and more often present with low-stage disease; survival for the various cell types is similar when stratified by stage. Borderline ovarian tumors can be subdivided into benign and malignant neoplasms, and in the view of some experts, this renders the borderline category obsolete. Women with typical serous borderline tumors (atypical proliferative serous tumors) constitute most of these patients and have virtually 100% survival, unless invasive peritoneal implants are present. Micropapillary serous carcinomas (a less common variant, also called serous borderline tumor with a micropapillary pattern) and tumors with invasive implants behave similar to low-grade invasive carcinomas.

Potential utility of uroplakin III, thrombomodulin, high molecular weight cytokeratin, and cytokeratin 20 in noninvasive, invasive, and metastatic urothelial (transitional cell) carcinomas

The morphology of urothelial carcinomas, particularly when poorly differentiated or in metastatic sites, is not distinctive and overlaps significantly with other poorly differentiated nonurothelial carcinomas. Currently, there is no widely used single marker or panel of markers to confirm urothelial origin. We evaluated a panel consisting of antibodies to uroplakin III (UROIII), thrombomodulin (THR), high molecular weight cytokeratin (HMWCK), and cytokeratin 20 (CK20) in a wide range of urothelial tumors. Immunohistochemistry was performed on 112 paraffin-embedded urothelial neoplasms: 14 low malignant potential, 16 low-grade noninvasive, 16 high-grade noninvasive, 36 invasive, and 25 metastatic and 5 small cell carcinomas of the urinary bladder. Tissue microarray analysis was used to examine 498 tissue cores of nonurothelial tumors and normal tissue using antibodies to UROIII, THR, and HMWCK. Overall positive staining results in all urothelial tumors are as follows: UROIII, 64 of 112 (57.1%); THR, 77 of 112 (68.8%); HMWCK, 88 of 110 (80%); and CK20, 53 of 110 (48.2%). The expression of the four markers varied with tumor grade and stage. All small cell carcinomas were negative for all markers. Variant morphologic subtypes showed similar staining as conventional urothelial carcinomas. Tissue microarray analysis showed no UROIII immunoreactivity in tissue cores of nonurothelial tumors. THR was expressed by a limited number of nonurothelial cores (10 of 37 [27%] non-small cell lung carcinomas, 2 of 36 [5.6%] lymphomas). HMWCK was expressed by 43.8% of non-small cell lung carcinomas and essentially absent in other nonurothelial tumor cores. Based on the results of the study, the expression of UROIII in a tumor is essentially diagnostic of urothelial origin; however, it is expressed in only slightly more than half of urothelial tumors. The coexpression of THR, HMWCK, and CK20 strongly suggests urothelial origin. The coexpression of two of three non-UROIII markers (THR, HMWCK, CK20) suggests urothelial origin but requires clinicopathologic correlation. The results of the study indicate a role for an antibody panel that includes UROIII, THR, HMWCK, and CK20 in the diagnosis of urothelial tumors.

Transitional cell carcinoma metastatic to the eye in a collared peccary (Tayassu tajacu)

A 15-year-old female collared peccary (Tayassu tajacu) was presented for ophthalmic examination following sudden onset of blindness. Bilateral retinal detachment was diagnosed, neoplasia suspected, and euthanasia performed. Widespread tumor dissemination was apparent at autopsy, and transitional cell carcinoma was diagnosed histologically. The tumor was identified as arising from the ovary. Epidemiologic features of this case are discussed.

Recent advances in immunohistochemistry in gynaecological pathology

Recent years have witnessed significant developments in the use of immunohistochemistry in diagnostic gynaecological pathology. This review details the most significant of these. In ovarian pathology, differential cytokeratin staining (CK7 and 20) assists in distinguishing between a primary ovarian adenocarcinoma and a metastatic adenocarcinoma, especially of colorectal origin. The development of markers characteristic of ovarian sex cord-stromal tumours (especially alpha-inhibin) facilitates diagnosis of these neoplasms which is often difficult by morphology alone due to the wide differential diagnosis. In the uterus, the distinction between a primary endometrial and endocervical adenocarcinoma may be facilitated by use of a small panel of antibodies, including CEA, ER and vimentin. Newly developed antibodies such as CD10 and h-caldesmon may be of use in the diagnosis of uterine mesenchymal lesions, especially in the distinction between endometrial stromal and smooth muscle lesions. Proliferation markers, such as MIB1, are of value in the cervix in the diagnosis of preinvasive squamous and glandular lesions. Recent studies have shown that cervical adenoma malignum exhibits a gastric phenotype. Advances have also been made in trophoblastic disease with the development of antibodies reactive against trophoblast such as alpha-inhibin, mel-Cam and p57. A newly developed monoclonal antibody HMGIC which is expressed in vulvovaginal aggressive angiomyxoma may prove to be of value in the often difficult distinction of this lesion from its histological mimics.

Immunohistochemical analysis of clear cell carcinoma of the gynecologic tract

Clear cell carcinoma of the gynecologic tract has been defined in terms of its clinical and histologic features; however, its immunophenotypic profile has not been fully characterized. Seventeen cases of primary clear cell carcinoma from various sites within the female genital tract (11 ovary, 5 uterus, 1 vagina) were analyzed by immunohistochemistry. These tumors were assessed for the expression of cytokeratin 7 (CK7), cytokeratin 20 (CK20), low and high molecular weight cytokeratin, (CAM5.2 and 34 beta E12, respectively), carcinoembryonic antigen (CEA), Leu-M1, vimentin, estrogen receptor (ER), progesterone receptor (PR), bcl-2, p53, HER-2/neu, and CA-125. The characteristic immunoprofile for all sites was positivity for CK7, CAM5.2, 34 beta E12, CEA, Leu-M1, vimentin, bcl-2, p53, and CA-125; variably positivity for ER and HER-2/neu; and negativity for CK20 and PR. For comparison, two cases of urologic clear cell carcinoma (1 bladder, 1 urethra) were also studied, and their profile was found to be similar to the gynecologic cases. Aside from minor differences, clear cell carcinoma appears to have the same immunophenotype regardless of whether it originates in the endometrium, ovary, or genitourinary tract. Much of its profile is similar to other gynecologic adenocarcinomas, but some of the markers studied may be useful in the differential diagnosis of this tumor.