A Morphologically Distinct Yet Seldom Seen Entity – Ovarian Collision Tumor

摘要

The co-existence of two adjacent and histologically distinct tumors in the same organ without histologic admixture at the interface are generically referred to as collision tumors. Although they have been reported in various organs, ovarian collision tumors are very rare. An ovarian teratoma with a cystadenoma or cystadenocarcinoma, typically of the mucinous type is the most commonly encountered combination. However, other histologic combinations are uncommon.We report a rare case of a 60 year old female presenting with pain abdomen since four months, radiologically found to have a left cystic ovarian mass and diagnosed histologically as benign serous cystadenoma with a mature cystic teratoma embedded within its wall. We intend to highlight the possible co- existence of ovarian collision tumors even when the clinicoradiological findings are suggestive of single ovarian neoplasm. A possible misdiagnosis of malignancy can be avoided if careful examination is undertaken pre and post operatively and histologically.