Histogenesis of Brenner tumors, II: histochemistry and CEA

Precursors and pathogenesis of ovarian carcinoma

The ultimate goal of defining cancer specific precursors is to facilitate early detection and intervention before the development of invasive malignancy. Unlike other malignancies involving the female genital tract such as cervical or endometrial carcinomas, precursor lesions of ovarian carcinomas have not been well characterised, resulting in a failure to develop effective screening programs. Recent clinicopathological and molecular studies have provided new insight into the origin and pathogenesis of ovarian carcinomas. It has been shown that ovarian cancer is comprised of different tumour types differing not only in morphology, but also in pathogenesis, molecular alterations and clinical progression. A dualistic model of ovarian carcinogenesis has been proposed. Type I tumours which include low grade serous, low grade endometrioid, clear cell, mucinous carcinomas and Brenner tumours, are generally indolent and tend to be genetically stable, although clear cell carcinoma would probably belong to an intermediate category. They demonstrate a step-wise progression from a benign precursor such as a benign to borderline tumour or endometriosis and are characterised by genetic aberrations targeting specific cell signalling pathways. Type II tumours comprise high grade serous, high grade endometrioid, and undifferentiated carcinomas as well as malignant mixed mesodermal tumours. They are clinically aggressive and exhibit high genetic instability with frequent p53 mutations. Mounting evidence suggests that many high grade serous carcinomas originate from the epithelium of the distal fallopian tube, and that serous tubal intraepithelial carcinoma (STIC) represents the putative precursor of these neoplasms. Low grade serous carcinomas arise via transformation of benign and borderline serous tumours, thought to be derived from inclusion cysts originating from the ovarian surface or tubal epithelium. Recently it has been suggested that papillary tubal hyperplasia may be a putative precursor lesion for serous borderline tumours. Both endometrioid and clear cell carcinomas develop from endometriosis, via alterations affecting different genetic pathways. The origin of mucinous and transitional cell neoplasms is not well characterised, although new data suggest a possible origin from transitional cell nests present at the tubal-mesothelial junction. Likewise, the pathogenesis of carcinosarcomas is also not well established because of their rarity but there is accumulating evidence that the carcinomatous component determines the course of the disease and gives rise to the malignant mesenchymal component. This review discusses recent developments in the pathogenesis of ovarian carcinoma, with particular emphasis on the putative precursor lesions that give rise to the major histological subtypes. Recognition of these lesions is not only important in improving the understanding of ovarian carcinogenesis, but it will also influence our approach to prevent, detect and treat these tumours.

[Brenner tumour of the vagina]

Vaginal tumours are rare, and Brenner tumour is one of the most infrequent vaginal lesions. Brenner tumour is a transitional tumour that typically arises in the ovaries. Some cases have been reported in the broad ligament, uterus and paratesticular structures. Only five cases have been reported in the vagina. We report a sixth case and discuss the histogenesis of this tumour, as well as the differential diagnosis with the mixed tumour of the vagina.

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.

Immunohistochemical analysis of uroplakins, urothelial specific proteins, in ovarian Brenner tumors, normal tissues, and benign and neoplastic lesions of the female genital tract

Uroplakins are the characteristic integral membrane proteins in terminally differentiated, superficial urothelial asymmetric unit membrane. Brenner tumors of the ovary and Walthard cell nests of Fallopian tubes have been considered to represent urothelial differentiation in the female genital tract, but no definitive differentiation marker has been demonstrated supporting such a conclusion. An immunohistochemical analysis was performed to assess the expression of uroplakins in these lesions as well as in various benign and neoplastic lesions and normal tissues of the female genital tract. Focal expression of uroplakins was observed on the luminal surface of ovarian Brenner tumor cells forming microcysts in all 5 cases examined. In contrast, uroplakins were slightly expressed in only 1 of 12 cases of Walthard cell nests, even in the presence of microcyst formation. Uroplakins were not expressed in other benign or malignant lesions or normal tissues of the female genital tract. These results support the hypothesis that the Brenner tumor and possibly Walthard cell nests represent urothelial (transitional cell) differentiation.

Case report of a malignant Brenner tumor with hyperestrogenism

A rare malignant Brenner tumor of the ovary presenting with hyperestrogenism in a 79 year old woman was examined immunohistochemically and by light and electron microscopy. High pre-operative serum and urinary estrogen concentrations, low serum luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels, and histologically confirmed atypical endometrial hyperplasia suggested the presence of hyperestrogenism. The reduction in serum and urinary estrogen and the increase in serum LH and FSH concentrations after tumor removal confirmed that the tumor was synthesizing estrogen. Histologically, the malignant element was predominantly a squamous cell carcinoma. Transitional cell carcinoma was partially found on the cyst wall. There was a spectrum of morphologic changes between benign and malignant elements with an intermediate area with a proliferating Brenner tumor. Immunohistochemically, only the carcinoembryonic antigen was positive exclusively on the malignant element as well as in the microcyst in the benign epithelial cord, whereas all of the markers for germ cell tumors were negative. The ultrastructural features of the stromal cells were of two types: fibroblasts and steroid-producing cells. The latter type of cells might correspond morphologically to estrogen-producing cells. The present case is the fourth report showing a malignant Brenner tumor combined with apparent hyperestrogenism.

Brenner tumor of the ovary: a correlative histologic, histochemical, immunohistochemical, and ultrastructural investigation

The histologic, histochemical, immunohistochemical, and ultrastructural features of Brenner tumor (BT) were studied. BT was compared with transitional bladder cells, and close similarities between the two tissues were identified. Abundant glycogen in all cellular layers, an alcianophilic/sialomucinic surface mucous coat, and argyrophilic cells characterized both BT and bladder epithelium. Immunohistochemically, chromogranin and neuron-specific enolase reactivity was observed in all cases examined. An additional relevant finding was the presence of serotonin-storing cells in both BT and urothelium. Moreover, carcinoembryonic antigen, epithelial membrane antigen, and keratin reaction were found in BT and urothelium, indicating an additional antigenic similarity. Additionally, malignant Brenner tumor was ultrastructurally found to share many common features with the bladder tissue. The distinct histochemical, ultrastructural, and antigenic pattern of BT, primarily of the transitional type, is emphasized.

Proliferative and malignant Brenner tumours (BT) and their differentiation from metastatic transitional cell carcinoma of the bladder: a case report and review of the literature

Up to now 110 cases of malignant Brenner tumour (BT) and 45 cases of proliferative BT have been reported in the accessible literature. To delineate the diagnostic criteria and to determine the differences between these tumours and metastatic tumours of the urinary tract, 94 cases of malignant BT and 37 cases of proliferative BT were reviewed. The difficulties encountered in determining these differences are illustrated by means of a case history.

Malignant Brenner tumor with peritoneal metastasis

A case of malignant Brenner tumor with peritoneal metastasis in a 67-year-old woman was reported. The multilocular cystic tumor of right ovary was 420 g in weight, and their cystic walls were covered with multilayered tumor cells showing papillary pattern very frequently. The tumor was histologically transitional cell carcinoma with occasional glandular structures but no squamous differentiation corresponding to grade 2 or 3 urinary bladder carcinoma. The pattern of benign Brenner tumor was not identified, but there was some area of proliferating Brenner tumor. Immunohistochemically, carcinoembryonic antigen was detected in several tumor cells, especially in the intercellular spaces among them, and cytokeratin was detected only in some tumor cells. Ultrastructurally, the malignant Brenner tumor shared many common features with the benign one and also bladder tumor. Intercellular spaces with microvilli were frequently found and thought to be important for diagnosis. The morphologic criteria of this rare tumor are discussed.

Brenner tumours of the ovary: a study of the histology, immunohistochemistry and cellular DNA content in benign, borderline and malignant ovarian tumours

Brenner tumours are now generally regarded as being of ovarian epithelial origin. Most have a limited growth potential and are benign. For this reason they are usually found incidentally at hysterectomy. In common with other epithelial ovarian tumours there is a histopathological spectrum of appearances ranging from benign through borderline to invasive malignancy. In this series all 54 tumours were graded according to the degree of cytological atypia, presence of mitoses and tumour necrosis. Heterogeneity of DNA content was observed in the higher grade tumours, two of the four being diploid and two being aneuploid (all benign tumours being diploid). The presence of aneuploidy correlated with the histological features and a poor clinical prognosis. Immunohistochemical staining for keratoprotein was found to be of limited value in the diagnosis of Brenner tumours and their metastases.

Estrogen synthesizing rare malignant Brenner tumor of the ovary with the presence of progesterone and androgen receptors in the absence of estrogen receptors

A case of a malignant Brenner tumor of a postmenopausal woman presenting with vaginal bleedings is described. Clinical and laboratory findings demonstrated estrogenic secretory function and action. The presence of aromatase activity based on in vitro tumor microsomal metabolism of androgen to estrogen is described. Tumor cytosol contained progestin and androgen binding components in the absence of estrogen binding activity. Estrogen binding activity was undetectable both by biochemical as well as histochemical assays.

Malignant Brenner tumor. A histologic, morphometrical, immunohistochemical, and ultrastructural study

The histologic, morphometric, immunohistochemical, and ultrastructural study of a malignant Brenner tumor in a postmenopausal women presenting with vaginal bleeding is described. A comparison with transitional cell carcinomas is made, and the use of morphometry in grading the urothelial-like epithelium in malignant Brenner tumors is suggested. High preoperative urinary estrogen, low serum luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels and histologically confirmed atypical endometrial hyperplasia suggested a hyperestrogenism. The reduction in urinary estrogen and the increase in serum LH and FSH after tumor removal and the presence of aromatase activity detected in tumor microsomes confirmed that the tumor was synthesizing estrogen. Estrogen receptors were undetectable both by biochemical and histochemical analysis in the tumor.

Ovarian Brenner tumors. II. Malignant

In this study, nine malignant Brenner tumors were reviewed and divided into well and poorly differentiated types. To meet the criteria for malignancy, stromal invasion must be observed. A component of typical benign, metaplastic, and/or proliferating Brenner tumor should be identified. The presence of these latter elements is necessary because the malignant component is often too poorly differentiated to be identified as a Brenner tumor, and a metastatic lesion cannot otherwise be ruled out on pathologic grounds. Well-differentiated tumors often occurred in close relationship to proliferating and occasionally to metaplastic areas, and poorly differentiated ones in relationship to low malignant potential areas. The malignant component may consist of transitional cell, squamous, or undifferentiated carcinoma or an admixture of these. A component of adenocarcinoma may be associated with other malignant elements, but pure mucinous or serous adenocarcinomas would be regarded as separate neoplasms. Although the number of cases is small, the well-differentiated tumors appear to have a better prognosis than the poorly differentiated ones.

Proliferative Brenner tumor or ovarian metastases? A case report

A case of low-grade superficial transitional papillomas of the urinary bladder and concomitant bilateral ovarian tumors with close similarities to the rare proliferative Brenner tumor is reported. Due to lack of benign Brenner elements, metastases from the bladder tumors were suggested. Death was apparently related to the effect of chemotherapy, and metastases were never confirmed. In review of the case, the authors found that the morphologic appearances and biological behavior of the ovarian tumors were more consistent with a proliferative Brenner tumor than with metastases. It is pointed out that a proliferative Brenner tumor should not be excluded in the absence of benign Brenner elements when other features are characteristic. Bilateral proliferating Brenner tumors are probably not reported previously. Histogenetic implications of a combined proliferative complex of bladder papillomas and Brenner tumor are briefly discussed.

Malignant Brenner tumor of the ovary. Electron microscopic study of a case responsive to radiation and chemotherapy

A patient with malignant Brenner tumor of the ovary is presented. The tumor responded to combined therapy with radiation plus doxorubicin + cyclophosphamide despite earlier failure on a single alkylating agent (levophenylalanine mustard). The patient next exhibited a brief response to chemotherapy with hexamethylmelamine + cyclophosphamide + amethopterin + 5-fluorouracil. The histologic findings and ultrastructure of the tumor are discussed in detail. The morphologic features are consistent with the proposed origin of Brenner tumors from coelomic epithelium through a process of secondary urothelial metaplasia.

Carcinoembryonic antigen localization in benign and malignant transitional epithelium

Transitional epithelium from 30 cases, including transitional cell carcinoma of various grades and stages, carcinoma in situ, cystitis cystica, and glandularis, as well as normal bladder epithelium, was studied for carcinoembryonic antigen (CEA) content by the immunoperoxidase technique. The results indicate that CEA is present in normal transitional epithelium and that its level frequently decreases in transitional cell carcinoma. These results are related to the findings in studies of urinary CEA excretion.