Struma Ovarii- A Rare Tumour with an Unusual Presentation

A teratoma composed predominantly or exclusively of a single type of tissue is called monodermal teratoma. Struma Ovarii (SO), a type of monodermal teratoma, is a rare variant of ovarian teratoma composed mainly of mature thyroid tissue. It is usually benign in histology. This is a case of an unusually large cystic ovarian mass reported as SO in a 43-year-old female patient who reported with complaint of acute retention of urine for one day, associated with pain in lower abdomen and distension.