Ovarian Brenner tumors. II. Malignant

Benign Brenner tumor of the ovary: two-dimensional and contrast-enhanced ultrasound features-a retrospective study from a single center

Objective

Benign Brenner tumor (BBT) is a rare ovarian tumor, and there are few discrete reports about its manifestation in an ultrasound. This study sought to investigate the two-dimensional (2D) and contrast-enhanced ultrasound (CEUS) features of this entity.

Methods

This is a retrospective single-center study. The clinical manifestations, laboratory examination, and ultrasound data of 25 female patients with BBT were confirmed by pathology when they underwent 2D and/or CEUS examination at Ningbo First Hospital from January 2012 to June 2023. The ultrasound findings of the patients were analyzed using the terminology of the International Organization for the Analysis of Ovarian Tumor and were read by two senior sonographers who reached an agreement.

Results

Among the all 25 patients, most of them were unilateral, and only one patient was bilateral. Thus, 26 lesions were found: 44.0% (11/25) were in the left and 52.0% (13/25) were in the right. Moreover, 53.84% (14/26) were solid lesions, 15.38% (4/26) were mixed lesions, and 26.92% (7/26) were cystic lesions. Among the solid-type patients, 42.85% (6/14) of the cases were with calcification. Upon laboratory examination, 12.0% (3/25) of the patients had high carbohydrate antigen 125 (CA-125) level, and 19.04% (4/21) of the patients had an elevated carbohydrate antigen724 (CA-724) level in the serum tumor markers. In the hormone test, 14.28% (3/21) were found to have a high postmenopausal estrogen level and 14.28%(3/21) were found to have a high level of follicle-stimulating hormone (FSH). One patient with complex manifestations and three with solid manifestations were examined by CEUS to observe the microcirculation perfusion of the tumor. One with solid and cystic separation was rapidly hyperenhanced and cleared, and the filling subsided faster than the uterus. The postoperative pathological diagnosis was benign Brenner tumor with mucinous cystadenoma. The other three cases were solid adnexal lesions, which showed isoenhancement on CEUS and disappeared slowly, synchronizing with the uterus. The CEUS results were considered as benign tumors and confirmed by pathology.

Conclusions

BBT can show ovarian cystic, mixed cystic and solid type, and solid echo in 2D ultrasound. Unilateral ovarian fibrosis with punctate calcification is an important feature of BBT in 2D ultrasound. However, for solid adnexal masses and mixed cystic and solid masses with unclear diagnosis, if CEUS shows isoenhancement or hyperenhancement, the possibility of BBT cannot be excluded.

Malignant Brenner tumor of the ovary: Review and case report

Ovarian neoplasms are a heterogeneous group of tumors with varying incidence in the general population. The most common are the surface epithelial tumors which include transitional cell tumors. Transitional cell tumors include both transitional cell carcinoma and Brenner tumor. The vast majority of Brenner tumors are benign, often incidental findings; however, malignant Brenner tumors (MBT) do occasionally occur. MBT present similarly to other ovarian neoplasms with abdominal pain and bulk symptoms. On imaging, these tumors demonstrate nonspecific findings. Microscopically, they demonstrate areas of conventional benign Brenner tumor juxtaposed with regions of frank malignancy showing marked cytologic atypia and infiltration. There is no consistent tumor marker for these tumors, but CA-125, CA 72-4 and SCC have been reported in singular instances. Tumors express several immunohistochemical markers of urothelial differentiation including uroplakin III, thrombomodulin, GATA3, p63, as well as cytokeratin 7. The primary treatment modality is surgical excision. Due to their rarity, the precise role and regimen of adjuvant chemo-radiation therapy for MBT has not been established. We herein review a case of MBT with emphasis on primary treatment and treatment of recurrent disease, including the use of adjuvant pelvic radiation, discuss the current state of the literature and standards of practice regarding this malignancy.

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Histologic differentiation of MBT from TCC is critical for diagnosis.

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Surgical staging should be performed for all cases of MBT.

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The role of adjuvant strategies for MBT is poorly defined.

[Malignant Brenner tumor with very good response after chemotherapy: about a case and review of the literature]

La tumeur de Brenner est une lésion ovarienne rare représentant 1 à 2% de l'ensemble des tumeurs ovariennes. Elle a été décrite pour la première fois par MacNaughton-Jones en 1898. La tumeur de Brenner maligne est une variante exceptionnelle survenant dans 2 à 5% des cas de tumeurs de Brenner. Nous proposons de discuter à partir d'une observation clinique de tumeur de Brenner maligne diagnostiquée chez une patiente de 47 ans traitée par chimiothérapie puis chirurgie radicale, et à travers une revue de la littérature; les différentes particularités cliniques et anatomo-pathologiques de cette entité rare ainsi que leurs implications diagnostiques et thérapeutiques. Le traitement repose principalement sur la chirurgie. L'indication d'une chimiothérapie adjuvante ou néo-adjuvante reste controversée.

Malignant Brenner tumor of the ovary with transformation to trabecular carcinoid: an immunocytochemical and electron microscopic study

Ovarian Brenner tumors are typically of surface epithelial-stromal origin; however, cases associated with mature cystic teratoma and/or struma ovarii possibly have a teratomatous derivation. Although argyrophil cells have been described in ovarian Brenner tumors and in urinary bladder epithelium, we are not aware of any previous reports of carcinoid arising from a malignant Brenner tumor of the ovary. In this study, we describe an 85-year-old woman who had a low-grade malignant Brenner tumor with progressive proliferation of neuroendocrine cells and transformation to trabecular carcinoid as demonstrated by immunocytochemistry and electron microscopy.

Imaging in gynecological disease (7): clinical and ultrasound features of Brenner tumors of the ovary

OBJECTIVES

To describe clinical and ultrasound features of Brenner tumors of the ovary.

METHODS

In this retrospective study, the databases of the International Ovarian Tumor Analysis (IOTA) studies and one tertiary center were searched to identify patients who had undergone an ultrasound scan before surgery for an adnexal mass that proved to be a Brenner tumor. Twenty-eight patients with 29 Brenner tumors were included, most of which had been collected within the framework of the IOTA studies. An experienced ultrasound examiner reviewed available ultrasound images (available for 14 tumors), searching for a pattern specific to Brenner tumors.

RESULTS

Most patients were postmenopausal and asymptomatic. Twenty-four (83%) tumors were benign, two (7%) were borderline and three (10%) were malignant. Most benign tumors (17/24, 71%) contained solid components and manifested no or minimal blood flow on Doppler examination (19/24, 79%). Information about calcifications was available for 15 benign tumors, and in 13 (87%) calcifications were present. The five borderline and invasively malignant tumors contained solid components less often than did the benign ones (3/5, 60%) and were more richly vascularized on Doppler examination. Information about calcifications was available for four borderline or invasively malignant tumors, and in three (75%) calcifications were present.

CONCLUSION

We failed to demonstrate ultrasound features specific to Brenner tumors. A prospective study is needed to determine if ultrasound features of calcifications can discriminate between Brenner tumors and other types of ovarian tumor.

Clear cell carcinoma of ovary with squamous metaplasia: A unique histopathological observation

Squamous metaplasia though is commonly associated with ovarian endometrioid neoplasm, mixed mullerian tumor and Brenner tumors; it has not been described in an ovarian clear cell carcinoma. Unusual presence of squamous islands, either in the form of morules or keratin plaques, may create diagnostic difficulty in a clear cell carcinoma of ovary, and thus the other common associations should be ruled out. Here, we describe a case of clear cell carcinoma of the ovary, with both gross and microscopically identifiable squamous metaplasia. To the best of our knowledge, this is the first report on this rare association and should be documented for wider awareness.

A singular observation of a giant benign Brenner tumor of the ovary

INTRODUCTION

Brenner tumors are rare transitional cell tumors of the ovary. They are usually benign neoplasms, of solid or solid-cystic structure and small size. We describe the case of a benign, predominantly cystic Brenner tumor measuring 39 cm in diameter.

CASE REPORT

A 62-year-old woman presented to the outpatient visit complaining about vague abdominal symptoms such as constipation and meteorism. Ultrasonography and CT scan showed the presence of a voluminous cystic mass, with fluid content, displacing other intra-abdominal organs. The patient underwent elective surgical excision, and there were no complications. Definitive pathological examination showed a metaplastic benign Brenner tumor.

CONCLUSION

The largest benign Brenner tumors reported in literature have been up to 30 cm in size, and greater size has been thought to be a predictor of malignancy. We have seen, however, that it is possible for larger lesions of this type to have a completely benign behavior; consequently, a benign nature should not be excluded even in the event of a large ovarian lesion.

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.

Transitional cell tumor of the ovary: computed tomographic and magnetic resonance imaging features with pathological correlation

OBJECTIVE

To describe computed tomographic (CT) and magnetic resonance (MR) imaging findings of transitional cell tumors, including newly established transitional cell carcinoma, according to tumor type with pathological correlation.

METHODS

We retrospectively reviewed the CT and MR images of 22 patients with transitional cell tumors of ovary (14 benign Brenner, 2 borderline Brenner, 2 malignant Brenner, and 4 transitional cell carcinomas) for the following factors: size, location, configuration, signal intensity, staging, and accompanying ovarian tumors.

RESULTS

Sixteen tumors were detected on CT or MRI (8 benign, 2 borderline, and 6 malignant tumors), and the mean size of measurable tumors was 8.8 cm. Benign Brenner tumors were homogeneous solid (n = 6) or unilocular cystic (n = 2). Two borderline Brenner tumors were multilocular cystic. Malignant tumors, including malignant Brenner tumors and transitional cell carcinomas, were heterogeneous solid (n = 3) or multilocular cystic (n = 3). The signal intensity of solid components on T2-weighted images was isointense compared with that of muscle in benign and borderline Brenner tumors and hyperintense in malignant tumors.

CONCLUSIONS

The CT and MR appearance of transitional cell tumors varied according to tumor type. Benign Brenner tumors were homogeneous solid or unilocular cystic pattern, and malignant tumors were heterogeneous solid or multilocular cystic.

Ovarian spindle cell lesions: a review with emphasis on recent developments and differential diagnosis

Ovarian lesions composed of spindle cells comprise a heterogeneous group; most are neoplastic but several non-neoplastic conditions are also composed of spindle cells. This review discusses the main differential diagnoses of an ovarian spindle cell lesion, especially concentrating on the recent literature. The majority of ovarian spindle cell lesions fall into the broad category of fibromatous neoplasms whereas others in the sex cord-stromal group may also be composed of spindle cells, including thecomas, granulosa, and Sertoli-Leydig cell tumors and rarer neoplasms, such as sclerosing stromal tumor and signet-ring stromal tumor. In the recent past there have been several major contributions on various aspects of ovarian spindle cell lesions, including cellular and mitotically active cellular fibromatous lesions, smooth muscle neoplasms, and metastatic gastrointestinal stromal tumors. Other mesenchymal or epithelial tumors and mixed epithelial and mesenchymal neoplasms may also enter into the differential diagnosis of an ovarian spindle cell lesion. Several non-neoplastic lesions may be composed of spindle cells, including massive edema, ovarian fibromatosis, stromal hyperplasia, and stromal hyperthecosis. Morphology remains the mainstay in diagnosis but immunohistochemistry may be invaluable in certain circumstances, one example being the identification of a metastatic gastrointestinal stromal tumor within the ovary.

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.

Differential diagnosis, prognostic factors, and clinical treatment of proliferative Brenner tumor of the ovary

Brenner tumors are rare ovarian tumors displaying benign, borderline or proliferative, and malignant variants. The case of a 63-year-old woman with a proliferative Brenner tumor is presented and the histomorphological differential diagnosis of this tumor entity is compared to that of its benign and malignant counterparts. Light microscopy, immunohistochemistry, and electron microscopy were performed to allow discrimination from the other subtypes. Despite a considerable overlap of pathological features the differential diagnosis of proliferative Brenner tumor could be established. Electron microscopy allowed assessment of characteristic infoldings of the nuclear membrane that proved to be a valuable ultrastructural criterion. Considering that the vast majority of Brenner tumors are benign, precise identification of the small proportion of malignant tumors allows the extent of surgical therapy to be adapted.

Malignant Brenner tumor mimicking a primary squamous cell carcinoma of the cervix

An 86-year-old female presented with a necrotic cervical mass that was biopsy-proven squamous cell carcinoma. She had an elevated CA-125 and a pelvic mass. At surgery, this mass was found to be of adnexal origin and contiguous with the cervix. Histology showed a malignant Brenner tumor with abundant squamous differentiation eroding the cervix and simulating a primary cervical malignancy. We describe this case and review the literature on metastatic tumors to the cervix.

Ovarian Brenner tumors: MR imaging characteristics

This study describes the appearance of Brenner tumors on MR imaging and compares quantitative signal intensity measurements of Brenner tumors with that of other ovarian tumors. A search of pathologic and MR records disclosed patients who had MRIs showing Brenner tumors prior to surgical excision. Patients (21) with other surgically proven ovarian masses were randomly selected for comparison. MR imaging was performed at 1.5 T with phased array multicoils and fast spin echo T2-weighted images. Region-of-interest measurements of signal intensity (SI) were made to calculate signal intensity ratios (SIR = mass SI/muscle SI). Brenner tumors showed significantly lower SIR than other tumors on T2-weighted images (p = 0.004) and similar SIR on T1-weighted images. Brenner tumors show lower signal intensity on T2-weighted images than other non-fibrous ovarian tumors. This lower signal intensity may result from the extensive fibrous content of these tumors.

Advanced stage transitional cell carcinoma of the ovary

Primary transitional cell carcinoma (TCC) of the ovary has been recently recognized as a separate subtype of epithelial cancer. It has been proposed that recognition of such tumors is important on clinical grounds because of a favorable response to chemotherapy and an improved patient survival. The authors reviewed the histological and clinicopathologic findings of 58 patients with advanced stage (stages III and IV) ovarian cancer with a view to determining the frequency of TCC and confirming the favorable prognosis. Of these cases, 15 (26%) were reclassified as TCC; 13 were predominantly TCC, and 2 had a mixed pattern with approximately 50% of the tumor being TCC. TCC patients ranged in age from 44 to 70 years of age (mean, 57). Ten of the patients had stage III disease, and five were stage IV. The tumor was unilateral in 2 cases and bilateral in 11 (2 unknown). Tumor size varied between 3 and 23 cm. Of the stage III patients, five were optimally debulked, and five had residual disease. All patients received the same type of chemotherapy. The median overall survival was 28 months. There was no significant difference in the clinical outcome of patients with TCC compared with that of patients with serous carcinomas. These data suggest that TCC does not confer a favorable prognosis or better response rate to chemotherapy.

Malignant Brenner tumor of the ovary: two cases of unusual histologic features of relapsed tumors

This study focused on unusual histologic features observed in 2 relapsed Brenner tumors. Case 1: A 67-year-old woman had a malignant Brenner tumor. The tumor relapsed was squamous-cell carcinoma. Case 2: A 51-year-old woman had a proliferating and malignant Brenner tumor with mucinous metaplasia. The relapsed tumor was a well-differentiated mucinous adenocarcinoma. These cases suggest that: (1) the relapsed tumor cells survived chemotherapy; and (2) the relapsed tumor cells transformed.

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.

Transitional cell carcinoma of the ovary: a matched control study of advanced-stage patients treated with cisplatin-based chemotherapy

OBJECTIVE

The purpose of this study was to compare patients with advanced-stage transitional cell carcinoma of the ovary with those who had poorly differentiated serous carcinoma for surgical response and survival.

STUDY DESIGN

Sixty-two patients with transitional cell carcinoma were identified through a retrospective review and were matched with serous carcinoma patients for stage and residual disease. All patients received cisplatin-based chemotherapy. End points selected for analysis were surgical response, progression-free survival time, and survival time. Univariate and multivariate regression analyses were also performed.

RESULTS

The surgical complete response rate for patients with transitional cell carcinoma was 37%, compared with 11% for those with serous carcinoma (p < 0.001). The survival time was significantly longer for the patients with transitional cell carcinoma (median 52.3 vs 22.0 months) (p < 0.001). Multivariate analyses strengthened these findings.

CONCLUSION

Transitional cell carcinoma of the ovary is significantly more chemosensitive and associated with a better prognosis than the more common serous carcinoma.

Age contrast in ovarian pathology

BACKGROUND. Ovarian cancer accounts for approximately 23% of all gynecologic tumors and is the most common fatal gynecologic malignancy. These tumors can occur in women of all ages, but there are differences in the histologic types during various decades of life. CONCLUSIONS. During infancy and childhood, the predominant type of neoplasms are those of germ cell origin, such as teratomas, dysgerminomas, and endodermal sinus tumors. In adults, epithelial neoplasms, or tumors that originate from the epithelium that covers the ovarian surface, are the most common, accounting for almost 85% of all neoplasms after the age of 50 years. The peak incidence of benign epithelial tumors occurs between the ages of 20 and 40 years. Young women (30 to 40 years of age) are frequently affected by the so-called "tumors of low malignant potential," which have excellent prognosis. Older women, on the other hand, usually have the most aggressive forms of ovarian cancer, present with advanced disease, and have a dismal prognosis.

Ovarian metastases from cervical carcinomas other than pure adenocarcinomas. A report of 12 cases

Twelve cases of ovarian metastases from cervical carcinomas, most with clinical manifestations of ovarian involvement, are reported. The patients were 23-73 years of age (average, 43 years). The ovarian and cervical tumors were synchronous in eight patients; in three, ovarian tumors were discovered 10 months, 2.5, and 3 years after the detection of a cervical neoplasm. In one patient, the cervical tumor was not discovered until autopsy 7 months after presentation. Four patients had abdominal swelling or distention, three had vaginal bleeding, three had an abnormal Papanicolaou smear, and two had masses discovered during pelvic examination. The ovarian tumors, six of which were bilateral, ranged from 5-17 cm (average, 9.5 cm) in maximal dimension in 11 patients; in the 12th patient, the involved ovary was not enlarged. The cervical tumors were grossly evident in 10 patients. They were usually deeply invasive, often with extracervical extension. Four were squamous cell carcinomas; two, small cell carcinomas; one, a mixed small cell carcinoma and adenocarcinoma; one, a mixed poorly differentiated carcinoid and adenocarcinoma; two, adenosquamous carcinomas; one, a transitional cell carcinoma; and one, an undifferentiated carcinoma. Various features, including bilaterality of the ovarian tumors, the finding that the histologic features of the ovarian tumors typically were unusual for a primary ovarian neoplasm, and the presence of extensive extracervical disease, led to the conclusion that the ovarian tumors were metastatic from the cervix. Although ovarian metastases of cervical carcinoma are uncommon, this series illustrates that, occasionally striking examples with clinical manifestations of ovarian involvement occur.

Metastatic transitional cell carcinoma simulating primary ovarian malignancy

A case of metastatic transitional cell carcinoma (TCC) to the ovaries in a patient with prior grade I TCC of the bladder, which morphologically resembled a primary ovarian malignancy on computed tomography (CT), is described. Other tumors whose ovarian metastases can resemble primary ovarian tumors are also listed.

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.

Malignant Brenner tumor of the ovary

Three cases of stage III malignant Brenner tumor of the ovary in which chemotherapy or radiotherapy favorably altered the clinical courses are reported, and the literature is reviewed.

Selective expression of cytokeratin polypeptides in various epithelia of human Brenner tumor

A human ovarian Brenner tumor presenting a wide spectrum of benign and malignant histologic features was studied for its patterns of intermediate filament expression. All epithelial elements of the tumor, regardless of their morphologic type, contained cytokeratins as their only intermediate filament component. Differences were detected, however, between tumor nests that displayed transitional epithelium and those with squamoid features. These differences were manifested by the presence of cytokeratin 18, in the former type only, and by the abundance of cytokeratins 10/11 in the latter. We also detected mixed epithelial nests in which both features were present, suggesting that the transitional epithelium transforms in polar fashion into squamous epithelium. Examination of cytokeratin patterns found in urothelium and in the surface epithelium of the ovary pointed to certain differences from the Brenner tumor epithelia. The significance of these latter findings with regard to cellular transformation and histogenesis of the Brenner tumor are discussed.

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.

Ovarian Brenner tumors. I. Metaplastic, proliferating, and of low malignant potential

In several studies, attempts were made to establish criteria for distinguishing malignant Brenner tumors from proliferating and low malignant potential ones. Although these criteria can be applied to the majority of cases, there still exist tumors that present problems in classification. In applying the World Health Organization (WHO) criteria for Brenner tumors, the most important feature for distinguishing the intermediate forms from the malignant ones is the presence of stromal invasion in the latter. This feature has generally been considered difficult to employ because of the fundamental fibroepithelial nature of Brenner tumors, the stroma being derived from the ovarian stroma. A logical and relatively easily applicable classification of Brenner tumors is presented in this report. Although more complex than the WHO classification, it includes newly recognized variants of the Brenner tumor and avoids using the same terminology to describe different types and degrees of epithelial abnormalities. Fourteen unusual Brenner tumors were studied, intermediate between typical benign and frankly malignant ones, and were classified into 3 categories representing progressive epithelial abnormalities. These include metaplastic, proliferating, and tumors of low malignant potential. In none of these does stromal invasion occur. Each of these categories corresponds to a particular urothelial abnormality or neoplasm. Through this classification, a better understanding of the morphology and biologic behavior of unusual types of Brenner tumors can be expected.