Collision Tumors of the Ovary: Dermoid Cyst with Borderline Epithelial Ovarian Tumor with Metachronous Invasive Epithelial Carcinoma of Ovary- A Case Series

Collision tumor is defined as the coexistence of two or more Histologically distinct tumors adjacent to each other in the same organ without any histological intermixing. Although collision tumors can occur in many organs in the body, its occurrence in ovary is extremely rare. In our series of two patients, dermoid cyst was co-existing with borderline epithelial ovarian tumors in one patient, which is rarest of rare variety of collision tumors reported in ovary. In another patient, there was recurrence in the form of invasive epithelial ovarian malignancy. JMS 2018;21(1):37-39