Histogenesis of Brenner tumors, I: histology and ultrastructure

Mucinous Borderline Tumor Associated with Mesonephric-like Proliferation: Further Evidence for a Possible New Origin of Ovarian Mucinous Neoplasms

Some ovarian mucinous tumors are thought to originate from Brenner tumors and teratomas; however, data are limited on what could be the origin for the remaining tumors. We report a new case of ovarian mucinous borderline tumor/atypical proliferative mucinous tumor (MBT/APMT) co-existing with a mesonephric-like proliferation (MLP)/mesonephric-like hyperplasia (MLH). The patient was a 58-year-old woman who presented with a pelvic mass and abdominal pain. Pathology demonstrated an 11 cm MBT/APMT in the left ovary. In addition, the tumor contained one focal area (<1% of total tumor volume) of MLP/hyperplasia adjacent to, or intimately admixed with, mucinous epithelium, with an immunophenotype of diffuse Pax8 and Gata3 expression and negative TTF-1, ER, and PR staining. Pax8 was also weakly positive in the MBT/APMT component. Some mesonephric-like glands partially exhibited gastrointestinal-type mucinous metaplasia/differentiation. A polymerase chain reaction (PCR)-based Sanger sequencing demonstrated that a KRAS G12V mutation was present in both MLP/MLH and MBT/APMT components, providing further evidence to support their clonal relationship. We previously reported a series of similar cases and demonstrated a novel association between MLP, mesonephric-like adenocarcinoma and ovarian mucinous tumor. It is conceivable that benign MLPs may have ability to differentiate to lineage-specific mucinous lesions, and, as such, they may serve as a possible new origin of some ovarian mucinous neoplasms; in particular, Pax8-positive tumors. The current case provides additional evidence to support this theory.

Brenner tumor associated with rete ovarii: a histologic and immunohistochemical analysis of six cases exploring the relationship between these entities

The association of Brenner tumor (BT) with rete ovarii (RO) has been rarely alluded to in the literature. Both entities have debatable histogenesis. In this study of six cases of BT associated with RO, we describe the morphologic features and performed immunohistochemical staining for markers of Mullerian, Wolffian, mesothelial, and sex cord stromal derivation to explore the relationship between these entities. Histologically, all BTs were benign, microscopic, and incidental. RO was prominent and hyperplastic with gradual or abrupt transition to BT. In addition, focal areas of rete entrapped between BT nests were seen. All BTs were positive for GATA-3 and negative for PAX-8. Conversely, the RO in all cases was negative for GATA-3 and positive for PAX-8. WT-1 was positive in both entities. Sex cord stromal and mesothelial markers (other than WT-1) were negative in BT and RO. Although morphologically, BTs seem to arise from RO in these cases, they have a distinct immunophenotype. It is possible that at least some BTs arise from metaplastic changes in RO epithelium.

Amplification of MDM2 and Loss of p16 Expression: Do They Have a Role in Malignant Transformation of Ovarian Brenner Tumor?

OBJECTIVES

To review the significance of MDM2 and cyclin D1 expression and loss of p16 expression in malignant and borderline Brenner tumors (BTs) of the ovary.

METHODS

We describe 2 new cases of ovarian BT, 1 malignant and 1 borderline. We studied MDM2, p16, and cyclin D1 expression by immunohistochemistry in the benign, borderline, and malignant components of these 2 cases and in 5 additional cases of benign BT. We also reviewed and summarized the literature on the clinical, immunohistochemical and molecular characteristics of borderline and malignant BTs (BdBTs and MBTs).

RESULTS

Nuclear expression of MDM2 was seen only in the MBT. Loss of p16 expression was seen in both BdBT and MBT. Cyclin D1 expression was in proportion to the degree of malignancy. Amplification of MDM2, loss of CDKN2A (p16-encoding gene), and amplification of CCND1 (cyclin D1-encoding gene) were confirmed by commercial next-generation sequencing in the case of MBT.

CONCLUSIONS

We are the first to report immunohistochemical expression of MDM2 in an MBT. Amplification of MDM2 and loss of p16 expression may have a role in malignant transformation of BT.

A peculiar case report of extraovarian Brenner tumor arising in the omentum

Background

Brenner tumors almost always develop in the ovary. Exceptionally, extraovarian Brenner tumors have been reported in the lower abdomen or pelvic organs. Here, we introduce a peculiar case of an extraovarian Brenner tumor arising in the omentum.

Case presentation

A 43-year-old woman presented with a palpable abdominal mass. Computed tomography (CT) scan revealed a 9.0-cm solid mass in the omentum. The tumor was not associated with pelvic structures, including the ovaries. It was excised under the clinical impression of an extragastrointestinal stromal tumor or neurogenic tumor. Grossly, the mass was a well-circumscribed solid tumor, with yellow-tan cut surface and minute cystic spaces. Microscopically, the tumor showed well-defined epithelial nests with variable cystic changes embedded in an abundant fibrous stroma. The cells within the nests were reminiscent of benign urothelial cells in that they had oval, frequently grooved nuclei. The epithelial cells focally showed a gradual transition into the surrounding stromal cells with short spindled features. The urothelium-like cells were positive for pancytokeratin, WT-1, p63, CK7, uroplakin-III, and GATA-3 but were negative for CD34, CD10, CK20, c-KIT, DOG-1, PAX-8, and calretinin. Morphological and immunohistochemical features of the tumor were the same as an ovarian Brenner tumor, and so it was diagnosed as an extraovarian Brenner tumor.

Conclusions

Although the location of the tumor was very unusual, we could diagnose the tumor as an extraovarian Brenner tumor on the basis of the histologic and immunohistochemical findings. This is the first case of extraovarian Brenner tumor arising in the omentum near the stomach ever reported in the English literature.

Exploring the histogenesis of ovarian mucinous and transitional cell (Brenner) neoplasms and their relationship with Walthard cell nests: a study of 120 tumors

CONTEXT

The origin of and relationship between ovarian mucinous and transitional cell (Brenner) neoplasms are enigmatic. The reported association ranges from 1% to 16%, and whether there is an association with Walthard cell nests is unknown.

OBJECTIVE

To clarify the histologic relationship between mucinous and Brenner tumors.

DESIGN

A total of 40 mucinous cystadenomas, 67 Brenner tumors, and 13 combined tumors were studied. Peritoneal surfaces were examined for Walthard nests in 83 patients compared with 272 controls.

RESULTS

A total of 25% of tumors with a mucinous component contained a Brenner component, and 16% of tumors with a Brenner component contained a mucinous component. Most calcifications were spiculated (nonpsammomatous). In 6 combined tumors, the relative volume of the 2 components was less than 1:3000 (transitional-mucinous). Walthard nests were found in 50% of patients with Brenner tumors and 59% of patients with mucinous tumors. This was significantly higher than the 28% found in controls (P = .002 and P < .001, respectively). The number of fallopian tube blocks examined was correlated with the likelihood of finding Walthard nests, and accordingly, sampling accounted for 39% of the increase with Brenner tumors but strengthened the association with mucinous tumors.

CONCLUSIONS

The strong association of mucinous and transitional cell components, similar type of calcification, complementary size distributions, and frequent identification of a transitional component in the face of an exceedingly small estimated proportion of that component suggest that this association has been underestimated. The association of Brenner tumors with Walthard nests, although significant, appears weak and not strongly supportive of a histogenetic relationship. The stronger association of Walthard nests with mucinous tumors remains unexplained.

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.

Transitional cell carcinoma of the endometrium associated with a benign ovarian Brenner tumor: a case report

Transitional cell carcinomas (TCCs) of the endometrium are rare, and only 10 cases have been described to date. We report the case of a 46-year-old woman who developed both a TCC of the endometrium and a benign ovarian Brenner tumor. Such an association has not yet been reported in the literature. Immunohistochemical studies of the uterine tumor showed cytokeratin 7 positivity and cytokeratin 20 negative staining, which was consistent with a Müllerian derivation. Human papilloma virus (HPV) immunostaining as well as polymerase chain reaction (PCR) analysis using primers for HPV types 6, 11, 16, and 18 failed to detect viral DNA. The coexistence of a TCC of the endometrium and an ovarian Brenner tumor might be coincidental but raises the possibility of a field effect, as seen with multifocal endometrioid tumors or multiple urinary tract TCCs.

Brenner tumor of the ovary: a comparative immunohistochemical and ultrastructural study with transitional cell carcinoma of the bladder

Because of a fancied light microscopic resemblance to transitional epithelium (urothelium), Brenner tumor (BT) of the ovary is commonly described as a transitional cell neoplasm. An inability to detect a great deal of similarity between the two at the ultrastructural level prompted this electron microscopic study comparing 3 benign Brenner tumors with normal urothelium and 6 transitional cell carcinomas (TCC) of varying histologic grade from the urinary bladder. To complement the ultrastructural observations, the immunophenotype of 8 benign BTs was evaluated together with that of 12 TCCs of the bladder using antibodies to thrombomodulin (TM), cytokeratin 20, cytokeratin 7, and carcinoembryonic antigen (CEA), all of which have been shown to react with TCCs of urothelial origin. At the ultrastructural level, there was only limited evidence of a morphologic likeness between the epithelial cells of BTs and those of the benign or neoplastic urothelium. The immunophenotype of the two tumors also differed significantly in that there was no reactivity for TM or cytokeratin 20 in the BTs, while these markers were expressed in the TCCs. Both BTs and TCCs were positive for cytokeratin 7 and may express CEA.

Brenner tumor of the ovary: immunoanalysis of steroidogenic enzymes in 23 cases

Immunohistochemical analysis of cytochromes P-450 aromatase and P-450 17 alpha-hydroxylase, which catalyze the production of estrogens and androgens, respectively, was performed for 23 cases of ovarian Brenner tumor. Immunoreactivity for P-450 aromatase was observed in the epithelial cells of the tumor distinctly in two cases and faintly in four cases, while immunoreactivity for P-450 17 alpha-hydroxylase was seen in two cases. No immunoreactivity was observed in the stromal cells of the tumors, nor were luteinized cells observed in the cases examined. No correlation was observed between the immunoreactivity of cytochromes P-450 in the epithelial cells of the tumor and endometrial abnormalities. These findings, together with a review of the literature, suggest that the usual Brenner tumor is not associated with specific steroidogenesis. Rare massive Brenner tumors may, however, be capable of androgenic or estrogenic activity.

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.

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.

Homoeotic transformations in man: implications for the mechanism of embryonic development and for the organization of epithelia

Homoeotic transformations are substitutions of one body part for another which arise during embryogenesis or regeneration. They are well known among the Arthropoda but are not generally thought to occur in Man or other vertebrates. In this paper the occurrence and characteristics of 21 types of epithelial heterotopia and metaplasia are reviewed and it is concluded that they are fully comparable with the homoeotic transformations of the arthropods.. The transformations are concentrated in the gastrointestinal, urinary and female reproductive systems and typically appear as foci of ectopic epithelium with a sharp discontinuity of cell type at the edges of the patches. Most of the transformations occur in renewal tissues and must therefore be interpreted as changes in the states of determination (epigenetic codings) of the stem cells rather than changes between already differentiated cells. Most, but not all, of the transformations are between tissues whose precursors are neighbouring regions of a common cell sheet during early embryogenesis and which are therefore likely to have neighbouring epigenetic codings. Following the Cairns hypothesis for epithelial organization it is proposed that stem cells themselves are protected against changes in epigenetic coding but their daughter cells, normally destined to differentiate and die, are not. Homoeotic transformations may thus occur in situations in which daughter cells become promoted to stem cells which happens either during the growth phase of the organism or during tissue regeneration in the adult.

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.