Ovarian dermoid eroding into rectum and masquerading as recurrent rectal teratoma

Abstract

Despite the common incidence of ovarian teratomas, primary rectal teratomas are rare. At times an ovarian teratoma may erode into the rectum and mimic a primary rectal tumor. We report a case of an adolescent girl aged 16 years, who was operated on one and a half years ago for a primary rectal teratoma. Her rectal teratoma reappeared after one year. When an ultrasono- graphic examination of the abdomen ruled out a secondary pathology and an endoscopic biopsy ruled out malignant conversion, a local recurrence due to incomplete excision was concluded. With the intent to completely excise it from the rectal wall, a laparotomy was carried out which revealed a left ovarian dermoid eroding through the anterior rectal wall. The ovary, along with the dermoid, were excised and the rectal wall defect was primarily closed. Histopathological examination confirmed a benign teratoma of the ovary. This case is presented to highlight the fact that primary rectal dermoids are rare tumors and should be diagnosed with caution. An