Brenner tumor of the testis: A case report and review of the literature

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.

Molecular and Clinical Insights in Malignant Brenner Tumor of the Testis With Liver Metastases:A Case Report

Malignant Brenner Tumor (mBT) is extremely rare. Although BT are almost exclusive ovarian neoplasms, they may constitute a highly unusual tumor of the testis; in fact, only seven fully documented cases have been reported to date. Because of their rarity, the pathogenesis of these tumors has not been clarified and there is no standard therapeutic approach. We report the first case of epididymal mBT with synchronous, multiple, liver metastases and a very dramatic clinical course. Both primary tumor and metastasis were subjected to mutational analysis of 20 cancer associated genes. Primary tumor showed FGFR3 Tyr375Cys and PIK3CA His1047Arg missense mutations. Both mutations are reported as pathogenic in ClinVar database. The same FGFR3 mutation was present in liver metastasis. Based on these results we believe that the FGFR pathway could be an ideal candidate for personalized treatment, offering hope to a subset of patients with mBT. Personalized approach, including mutational analysis and molecular testing should be required in patients with rare tumors in order to clarify diagnosis and improve therapeutic strategies.

The mutational frequency of BRAF and KRAS in low-grade serous testicular neoplasms-a case series

AIMS

Low-grade serous neoplasms of the testis are rare neoplasms that show striking morphological similarities with the better-understood ovarian neoplasms. This study is to see if there are similar molecular abnormalities in these two tumours. The cell of origin, relationship with serous ovarian tumour and the pathogenesis of these neoplasms are not fully established.

METHODS AND RESULTS

As low-grade serous ovarian neoplasms are known to harbour mutations in the MAPK pathway, we investigated the involvement of BRAF and KRAS mutations in low-grade testicular serous tumour by performing mutational analysis of seven cases. Mutational analysis was performed by melting curve analysis followed by bidirectional sequencing. Our findings showed BRAF and/or KRAS mutations in three of the seven cases, which is similar to the proportions reported in low-grade ovarian serous neoplasms. Of these three cases, one showed co-mutation of BRAF and KRAS.

CONCLUSION

The findings of this study are in support of a role of aberrant signalling of the MAPK pathway in the pathogenesis of low-grade serous testicular neoplasms, and provide a genetic link between low-grade testicular and ovarian serous tumours.

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.