Poorly differentiated Sertoli-Leydig tumor with heterologous, high-grade, sarcomatoid features: A case report.

•Treatment of sex-cord stromal tumors with carboplatin and taxane is both feasible and safe.•FOXL2 mutations account for approximately 50% of these tumors.•Carboplatin and taxane may afford a favorable outcome.

Malignant peritoneal mesothelioma without asbestos exposure: An ovarian cancer imitator.

•Malignant peritoneal mesothelioma is a rare aggressive tumor with approximately 400 new cases annually in the US.•In optimal cytoreduction HIPEC is the standard treatment.•In suboptimal cytoreduction IV cisplatin and pemetrexed have high efficacy.

Primary intraplacental gestational choriocarcinoma: histologic and genetic analyses.

Gestational choriocarcinoma is a highly malignant form of gestational trophoblastic tumors. Placental involvement of the tumor is exceedingly rare. We describe a case of intraplacental choriocarcinoma in a full-term placenta.

Malignant melanoma arising in mature cystic teratoma of the ovary.

► Teratomas are composed of elements of all three germ layers, all potentially capable of undergoing malignant transformation. ► A case of malignant melanoma arising in a mature teratoma is presented.