Carcinomas of the endometrium and ovary with undifferentiated components are uncommon neoplasms that are likely underdiagnosed. They are important to recognize as they have been shown to be clinically aggressive. We identified 32 carcinomas with undifferentiated components as defined by Silva and co-workers, 26 endometrial and 6 of ovarian origin. The patient age ranged from 21 to 76 years (median 55); 40% of patients were r50 years of age. Most patients (58% of endometrial and 83% of ovarian carcinomas with undifferentiated components) presented at advanced stages (FIGO III-IV). Pelvic and para-aortic lymph nodes were the most frequent sites of metastases. Twenty tumors, entirely undifferentiated, consisted of sheets of dyshesive, ovoid cells with uniform, large vesicular nuclei, whereas 12 tumors contained combinations of differentiated endometrioid adenocarcinoma with undifferentiated components. Although most undifferentiated tumors had a monotonous cytologic appearance without prominent stroma, six showed focal nuclear pleomorphism and eight cases had variably sized zones of rhabdoid cells in a background of myxoid stroma. The tumors were frequently misdiagnosed; they received a wide range of diagnoses, including FIGO grade 2 or 3 endometrioid carcinoma, carcinosarcoma, high-grade sarcoma including endometrial stromal sarcoma, neuroendocrine carcinoma, lymphoma, granulosa cell tumor and epithelioid sarcoma. Up to 86% of the cases showed focal, but strong keratin and/or epithelial membrane antigen staining, with CK18 being the most frequently positive keratin stain. They were predominantly negative for neuroendocrine markers, smooth muscle markers and estrogen receptor/progesterone receptor. Mismatch repair protein expression by immunohistochemistry was evaluated in 17 cases, and 8 (47%) were abnormal (7 with loss of MLH1/PMS2 and 1 with MSH6 loss). Follow-up was available for 27 patients, although it was very short in many cases, ranging from 0.5 to 89 months (median 9 months). Eleven patients (41%) died of the disease in 0.5-20 months, four are alive with disease and twelve patients have no evidence of disease. Endometrial and ovarian carcinomas with undifferentiated components have a broad histologic differential diagnosis, but they show specific histologic features that should enable accurate diagnosis. These tumors can occur in young women, may be associated with microsatellite instability and behave in a clinically aggressive manner.

This study was undertaken with the hypothesis that certain common morphologic features of ovarian carcinomas are predictably associated with BRCA1 and BRCA2 deficiencies. We selected 43 high-grade serous carcinomas diagnosed at Memorial Sloan-Kettering Cancer Center that were studied as part of The Cancer Genome Atlas pilot project. In addition to 12 randomly selected nonfamilial BRCA-unassociated cases, all 31 Memorial Sloan-Kettering Cancer Center cases with BRCA1 or BRCA2 abnormality were included (n ¼ 43). Slides were examined to assess tumor architecture, mitotic index, tumor-infiltrating lymphocytes (TILs), nuclear pleomorphism, necrosis, and involvement of fallopian tube epithelium. Comparing BRCA1-associated cases (BRCA1 germline mutation, n ¼ 4, BRCA1 somatic mutation, n ¼ 6, BRCA1 promoter methylation, n ¼ 13) with unassociated cases (n ¼ 12) identified statistically significant differences in morphology. BRCA1-associated high-grade serous carcinomas had more frequent Solid, pseudoEndometrioid, and Transitional cell carcinomalike morphology (SET features) (P ¼ 0.0045), higher mitotic indexes (P ¼ 0.012), more TILs (P ¼ 0.034), and either geographic or comedo necrosis (P ¼ 0.034). BRCA2-associated cases (germline mutation, n ¼ 4 and somatic mutation, n ¼ 4) tended to show SET features, but they were relatively deficient in TILs and necrosis. Two algorithms incorporating tumor architecture, necrosis, and either mitotic indexes or TILs separated cases that showed 2 of 3 features (BRCA1 associated) from those with 0 of 3 features (BRCA unassociated; P ¼ 0.0016 and P ¼ 0.0033). A test set comprising 9 BRCA1 germline mutants and 14 high-grade serous carcinoma controls lacking BRCA1 and BRCA2 germline mutation was used to validate the algorithms, with specific emphasis on the ability to detect cases with BRCA1 germline mutation. Best results were obtained with the algorithm that incorporated SET features, necrosis, and mitotic index (P ¼ 0.0072; sensitivity of 1.0 (95% CI, 0.66-1.0); specificity of 0.57 (95% CI, 0.29-0.82); positive predictive value of 0.60 (95% CI, 0.32-0.84) and a negative predictive value of 1.0 (95% CI, 0.63-1.0)). These preliminary data indicate potential strong associations between morphology and genotype in high-grade serous carcinomas.

Background Low-grade serous (LGS) ovarian cancer (OC) is a chemoresistant disease that accounts for 10% of serous ovarian cancers. Prior studies have reported that 28–35% of serous borderline (SB)/LGS ovarian tumors harbor a BRAF mutation, suggesting that BRAF inhibitors may be a rational therapeutic approach for this disease. We sought to determine if BRAF or KRAS mutation status is associated with disease stage and/or histology in patients with SB and LGS ovarian cancer. Methods We genetically profiled 75 SB and LGS ovarian tumors for mutations in BRAF and KRAS. The incidence and identity of BRAF and KRAS mutations were defined and the results were correlated with stage, response to treatment, and overall survival. Results Of 75 samples examined, 56(75%) were SB and 19(25%) LGS histology. Fifty-seven percent of tumors harbored either a KRAS mutation (n=17) or a BRAF V600E mutation (n=26). BRAF V600E mutation was significantly associated with early stage disease (Stage I/II, P<0.001) and serous borderline histology (P=0.002). KRAS mutation was not significantly associated with stage or histology. Of the 22 (29%) patients who required treatment with chemotherapy, 20 were KRAS/BRAF wild-type (WT), 2 were KRAS mutant, and none had tumors harboring a BRAF mutation. All BRAF mutant patients were alive at a median follow-up of 3.6 years (range 1.9–129.3 months). Conclusions V600E BRAF mutations are present in 35% of SB/LGS ovarian cancers. The presence of BRAF V600E mutation in SB/LGSOC is associated with early stage disease and improved prognosis. Patients with SB/LGSOC who require systemic therapy are unlikely to have BRAF mutant tumors.

Women with hereditary nonpolyposis colorectal cancer (HNPCC) have a high risk for endometrial cancer (EC) and frequently present with a gynecologic cancer as their first or sentinel malignancy. Identification of these patients is important given their personal and family risk for synchronous and metachronous tumors. The revised Bethesda Guidelines provide screening criteria for HNPCC in colorectal cancers. However, there are currently no such screening recommendations for women with endometrial carcinoma. We applied some of the colorectal cancer screening criteria, including age and tumor morphology, to endometrial endometrioid carcinoma. The purpose of this study was to describe patient and tumor characteristics and to assess the ability of these criteria to enhance detection of mismatch repair (MMR) deficiency, and hence HNPCC in EC. Immunohistochemistry (IHC) for DNA mismatch repair (IHC-MMR) proteins was performed in a defined subset of patients with EC. This included women younger than 50 years of age and women >or=50 years whose tumors showed morphologic features suggestive of MMR deficiency (TM-MMR). The extent of IHC-MMR in the older patient group was compared with that in a comparison group of EC >or=50 years that was previously analyzed for microsatellite instability status. Seventy-one patients met the selection criteria for IHC testing; 32 (45%) showed abnormal results. The rate of IHC abnormality in the younger group was approximately 30% with a nearly equal distribution of MLH1/PMS2 and MSH2/MSH6 abnormalities. In the older age group, TM-MMR triggered IHC analysis in 31 of 34 cases. Of these, 18 cases showed loss of IHC-MMR (58% of cases), 7 with loss of MSH2/MSH6. In contrast, the rate of microsatellite instability in the comparison group was only 21%. The IHC abnormal group showed more frequent tumor infiltrating lymphocytes, dedifferentiated EC, more tumors centered in the lower uterine segment, and more frequent synchronous clear cell carcinomas of the ovary than tumors with a normal immunophenotype. Although many of the patients with loss of IHC-MMR showed personal and/or family history (13 of 32) of HNPCC-associated tumors, most did not. Tumor morphology (TM-MMR) along with IHC-MMR enhances the detection of EC patients at risk of HNPCC.

Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) syndrome is an autosomal dominant syndrome that results from mutations in the fumarate hydratase (FH) gene. Patients with HLRCC are at risk for smooth muscle tumors of the uterus and skin as well as renal tumors. The renal cell carcinomas associated with HLRCC are usually high stage at presentation, aggressive, and have poor clinical outcomes. Therefore these patients and family members would benefit from early identification and appropriate surveillance. In small studies, HLRCC-associated uterine leiomyomas have been noted to display characteristic morphologic features including eosinophilic cytoplasmic inclusions, prominent eosinophilic nucleoli, and perinucleolar halos. Limited data suggest that positive staining for 2-succinocysteine (2SC) and loss of staining for FH by immunohistochemistry (IHC) can help with identification of HLRCC. The aim of this study was to evaluate the ability of morphology and IHC for FH and 2SC to help identify HLRCC in young patients with uterine smooth muscle tumors. We identified 194 evaluable uterine leiomyomas from women less than 40 years of age. We found FH gene aberrations by mutation analysis in 5 cases, a 2.6% incidence. Of these 5 cases, 4 displayed the characteristic morphologic features outlined above, whereas 1 did not. All 5 tumors with FH gene abnormalities showed positive staining for 2SC, whereas no FH gene aberrations were found in the 2SC-negative cases. Loss of FH staining was seen in 2 of the 5 cases, 1 with frameshift mutation and the other with homozygous deletion, whereas the remaining 3 cases with missense FH gene mutations were FH positive. Our study shows that morphologic features can be helpful for detection of HLRCC in uterine leiomyomas, although they may not be present in every case. IHC for 2SC and FH can be helpful: presence of positive staining for 2SC is sensitive and specific for detection of FH gene aberrations, whereas loss of staining for FH is specific but not sufficiently sensitive, as cases with missense mutations in the FH gene can show retained staining.