Uterine collision tumor of endometrial stromal sarcoma and endometrioid adenocarcinoma: A rare case report and review of literature.

Collision tumors are characterized by occurrence of two or more histologically distinct tumor types at the same anatomic site. Collision tumors have been reported in various organs, such as esophagus, stomach, colon, kidney, lung, skin, thyroid, breast, ovary and uterus. Uterine collision tumors of epithelial and mesenchymal origin are rare and often underrecognized. We report a rare concurrent occurrence of endometrial stromal sarcoma and endometrioid adenocarcinoma in a 65-year-old female. It is important to differentiate collision tumors from carcinosarcoma due to impact on clinical management and prognosis. Extensive gross sampling and careful morphological examination aided by immunohistochemical studies is necessary for the diagnosis of this rare entity. This case report aims to increase the awareness of this rare pathological entity with discussion on the management issue based on review of literature. This is the first case in Indian literature to the best of our knowledge.