Sarcoma-Like Mural Nodule in a Borderline Mucinous Tumour of Ovary.

A 37-year female presented with complaint of lower abdominal pain and amenorrhoea to the Military Hospital, Rawalpindi. Ultrasound of pelvis showed a right adnexal cystic lesion. On investigation, CA-125 was raised. Her MRI scan of pelvis revealed a right adnexal mass of fluid intensity measuring 15.2 x 12.9 x 9.2 cm. Right ovarian cystectomy was performed and the specimen was sent for histopathological examination. Grossly, the mass was cystic in appearance and measured 13.5 x 10 x 10 cm. On sectioning, it was unilocular and filled with turbid material. The cyst wall showed multiple papillary structures along with a nodule measuring 1.1 x 1 cm. Microscopically, the sections revealed borderline mucinous tumour with a sarcoma-like mural nodule composed of spindle shaped cells and epulis-like giant cells. Sarcoma-like mural nodules are rare nodules which are associated with mucinous tumours of the ovary. However, they have excellent prognosis and should not be interpreted as malignant.