An ultrastructural study of the nature and origin of the Brenner tumour of the ovary

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.

Coexpression of cytokeratins and vimentin in common epithelial tumours of the ovary: an immunocytochemical study of eighty-three cases

An immunocytochemical investigation has been performed on 83 common epithelial tumours of the ovary, to ascertain their capability of expressing vimentin in addition to cytokeratins. Our results demonstrate that vimentin coexpression is related to the tumour histotype and -to a lesser extent- to the degree of differentiation of malignant variants. Indeed, most serous tumours (80%), some endometrioid adenocarcinomas, and all the clear cell carcinomas investigated exhibited a variable number of neoplastic cells co-synthesizing the two distinct intermediate filament (IF) proteins, whereas only one of 29 mucinous tumours and none of the Brenner tumours displayed vimentin-immunoreactive cells. Moreover, in serous and endometrioid carcinomas, the expression of vimentin was related to the degree of tumour differentiation, being consistently identifiable in the better differentiated cases. The immunocytochemical findings of a parallel investigation on IF expression in the ovarian coelomic epithelium and in the müllerian-derived epithelia of the female genital tract allowed us to ascertain that ovarian epithelial tumours (with the possible exception of poorly differentiated carcinomas) maintain the pattern of IF expression typical of the normal epithelia. This investigation emphasizes the usefulness of IF typing as a tool for the more precise characterization of the origin and differentiation of human neoplasms.

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.

Bilateral malignant Brenner tumor: report of a case with ultrastructural study

An unusual case of bilateral malignant Brenner tumor with liver and omental metastases is reported. The tumor was histologically a transitional cell carcinoma comparable to a grade III bladder carcinoma. A benign component was not identified, but there were a few nests of malignant epithelial cells distributed in a dense stroma, a pattern identical to that seen in a benign Brenner tumor. Whether this represents malignant change in a previously benign focus or a well differentiated part of a de novo carcinoma is unclear. Nevertheless it is suggested that the current histologic criteria for malignant Brenner tumor be modified to exclude the requirement of an intimately associated benign Brenner tumor. Ultrastructurally the malignant Brenner tumor has many features of the benign Brenner tumor. Some features, notably the basal lamina, micropinocytotic vesicles, nd intracytoplasmic microfibrils, are herein described for the first time in a malignant Brenner tumor.

Epithelial mucosubstances and argyrophil cells in Brenner tumours

Brenner tumours of various degree of malignancy were investigated by histochemical methods. The cells lining the cystic cavities in the benign Brenner tumours contained various amounts of PAS-positive, diastase resistant secretory material mixed with small amounts of sulpho- and carboxymucin. The borderline and malignant tumours contained more acidic mucins than the benign tumours. All tumours contained glycogen. Argyrophil and argentaffin cells have not earlier been detected in the Brenner tumours but in this study they were detected in twelve of the 18 Brenner tumours. These cells were not proliferating and therefore Brenner tumour should not be included in the group of APUDomas.

Ultrastructure of the benign and borderline Brenner tumours

One benign Brenner tumour and one Brenner tumour of borderline malignancy were investigated by electron microscopy. The cells of the benign Brenner tumour nests and the cells in the borderline tumour were similar in ultrastructure. The intercellular spaces were large and reinforced by a moderate number of desmosomes. The nuclei were round or oval. The nuclear membrane was irregular in shape with deep infoldings corresponding to the characteristic nuclear groovings seen by light microscopy. Only few secreting cells could be found in the benign of Brenner tumour. The cystic cavities of the borderline Brenner tumour were lined by nonciliated secreting and ciliated nonsecreting cells. The secretory granules were PAS-positive and diastaseresistant. The granules stained homogeneously and strongly with the PASM-method at the electron microscopical level indicating the presence of 1.2-hydroxyl groups. The Brenner tumours have many similarities to the transitional epithelium and to the Muellerian-derived tubular structures. The findings support the theory that Brenner tumours are of coelomic origin and develop by direct metaplasia from the ovarian surface epithelium.

Ultrastructure of gonadoblastoma and disgerminoma (seminoma) in a patient with XY gonadal dysgenesis

The gross and fine morphology of gonadoblastoma and disgerminoma in a young phenotypic female with male karyotype and gonadal dysgenesis is described. Both the rudimentary gonads contain gonadoblastomas on the left side in association with a disgerminoma. In the light microscope the gonadoblastomas show peculiar hyaline masses, surrounded by Sertoli-like cells. In some areas a direct continuation between hyaline masses and basement membranes of round nests or large anomalous seminiferous tubules is obvious. At the ultrastructural level the hyaline masses consist of densely packed, largely concentric membranes closely similar to basement membranes or basal laminae of seminiferous tubules. These observations and the finding of transitional zones with gonadoblastoma elements in enlarged tubular structures suggest that gonadoblastomas originate inside tubules of dysgenetic testes. The peculiar hyaline masses with their concentric membranes might reflect hyperplasia and death of the Sertoli cells, each new generation of cells producing a basement membrane outside the preceding one.

Brenner tumor of the uterus

Extraovarian Brenner tumors are extremely rare. Three paratesticular lesions have been observed in men. The only extraovarian Brenner tumor in a woman previously reported was located in the broad ligament. This paper describes a small tumor with histologic features of Brenner tumor within the wall of the uterus. The possible histogenesis is briefly discussed.