Collision Tumor of Ovary Associated With Contralateral Benign Cystic Teratoma in Primigravida: A Case to Remember

Abstract

Collision tumors involving ovaries are extremely rare. Here, we report this rare entity in a 23 years old primigravida presented with 12 weeks pregnancy and abdominal pain. Ultrasonography showed large right adnexal mass measuring 20 x 13 cm. having solid area with multiple cysts and bulky left ovary of 6 x 4.6 cm. Normal ovarian tissue was preserved after bilateral ovarian cystectomy. Grossly, right ovarian tissue revealed multiloculation and mucin filled cysts. Left ovarian cyst was filled with hairy pultaceous material. Histological diagnosis of collision tumor of right ovary comprising hemorrhagic mucinous cystadenoma and benign cystic teratoma along with dermoid cyst in left ovary was rendered. The pathogenesis of association of mature cystic teratoma with a mucinous cystadenoma has yet to be answered and the choice of management necessitates a weighing of risks based on characterization of the adnexal mass and gestational age.