Mature Teratoma with Malignant Brenner Tumour: A Rare Ovarian Collision Tumour Case Report and Literature Review.

Collision tumor is existence of distinct tumors in the same tissue or organ without admixture. Although any histological type of ovarian tumor may occur in collision tumor, the mature teratoma is one of the most found component. Brenner tumor is a rare epithelial tumor of ovary and the coexistence of it with teratoma in collision tumour is sparsely reported in literature. Here we describe a case of mature teratoma with malignant Brenner tumor diagnosed post-operatively on histopathological and immunohistochemical examination. It is of paramount importance to correctly diagnose the histological components of collision tumor as it decides further management and course of the disease.