Differentiating uterine serous carcinoma (USC) from endometrioid adenocarcinoma (EAC) could be problematic, especially in high-grade EACs and tumors exhibiting architectural variations. To address this issue, we evaluated 103 endometrial carcinoma cases using 4 immunomarkers, beta-catenin, IMP3, PTEN, and p53. Cases included 31 USCs, 57 EACs, and 15 mixed EAC-USCs. Of 31 USCs and 57 EACs, 8 and 9, respectively, were considered diagnostically difficult and challenging. beta-catenin was more frequently expressed in EAC (P = .001); p53, PTEN, and IMP3 were more frequently found in USC (P < .001 for each). IMP3 was the best independent predictive marker for USCs. The best marker combination for predicting USCs was PTEN+/IMP3+ (exact odds ratio, 163.87; 95% confidence interval, 19.62 to infinity; P < .001). IMP3 was consistently negative in all 9 challenging EAC cases and consistently positive in all 8 challenging USC cases. None of the markers or their combinations demonstrated any value in making the diagnosis of serous component in mixed EAC-USC tumors. IMP3 immunoexpression and the IMP3+/PTEN+ pattern are the best independent and combination markers, respectively, to predict USCs. We strongly recommend using them in difficult and challenging cases.

Epithelioid sarcoma of the vulva is an extremely rare neoplasm with aggressive behavior and poor outcome. Herein, we report a case of vulvar epithelioid sarcoma presenting in a 17-year-old very early in her pregnancy. The patient presented with an asymptomatic nodule of the right labia majora of 1-year duration. Computerized tomographic scans showed enlarged inguinal lymph nodes and numerous lung nodules. Positron emission tomography was performed and revealed no suspicious lesions for metastatic disease. The patient underwent local excision of her vulvar lesion. On the basis of morphology and extensive immunohistochemistry, the lesion was classified as epithelioid sarcoma. The patient was referred to radiation therapy and upon evaluation, she was found to be in her sixth week of gestation. The patient continued with her pregnancy and underwent a lymph node dissection, which was positive. We review the literature of only the well-documented cases extensively studied by immunohistochemical analysis. We summarize the clinical presentation, clinical impression, treatment modalities, and outcomes of these cases. On account of the rarity of this disease in the vulva, there is no clear consensus on treatment modalities, but it seems that early aggressive surgical resection is the treatment of choice, with the role of adjuvant therapy to be determined.