Gastrointestinal stromal tumour: presenting as an ovarian cystadenoma.

A gastrointestinal stromal tumortumour (GIST) is an uncommon gastrointestinal neoplasm that can arise from any part of the gastrointestinal tract. They can rarely present as a pelvic mass, which might result in a gynaecological condition being misdiagnosed in a female patient. A woman in her early 70s presented with a huge pelvic mass. Abdomen-pelvis CT scan showed a significant cystic mass in the left-sided pelvis with a mass effect on adjacent structures, which suggested a possibility of an ovarian cystadenoma. Her CA-125 was normal. She underwent an exploratory laparotomy with pelvic mass excision. A diagnosis of a gastrointestinal stromal tumour (GIST) arising from the ileum was made on a histopathology study.