Collision tumours of ovary: a very rare case series.

Collision tumours are composed of two histologically distinct neoplasms in the same organ without intermixture of cell types. Here the author present a case series of 4 cases of collision tumours of ovary with brief review of literature. Two cases have a combination of mucinous cystadenoma and teratoma whereas third case is a combination of serous papillary cystadenoma with teratoma and the fourth case has a combination of serous papillary cystadenocarcinoma and teratoma. The cases were diagnosed post-operatively. It is important to correctly diagnose the component of tumour for further management and favourable prognosis.