Other rare ovarian cancers: Transitional cell carcinoma, malignant Brenner tumor, endometrioid carcinoma, mesothelioma, squamous cell carcinoma, sarcoma

This chapter reviews the epidemiology, clinical presentation, diagnosis, pathology, treatment, surveillance guidelines, and treatment for recurrences for ultrarare ovarian malignancies based on the existing literature and by drawing from similar histologic subtypes from other primary tumor sites. Ovarian cancers are typically classified as epithelial cancers, which comprise 90% to 95% of all ovarian cancer cases, and nonepithelial cancers. Furthermore, among the nonepithelial cancers, there are a group of ultrarare subtypes, which include transitional cell carcinoma, endometrioid carcinoma, neuroendocrine tumors, mesothelioma, squamous cell carcinoma, and ovarian sarcomas. Scarce data exist on the diagnosis, treatment, management, surveillance, and recurrence treatment for these ultrarare subtypes of nonepithelial ovarian cancer, as most information comes from small case reports or case series. While there are some guidelines for management of these tumors, most of the current practice recommendations are extrapolated from guidelines for more common cancers with similar histology.