Widespread endometriosis mimicking ovarian malignancy: a case report.

A 26 year old Nigerian nulliparous woman who presented in the medical emergency unit of a teaching hospital was referred after two weeks of management to the gynecology casualty with a diagnosis of malignant left ovarian cyst, because of the ascites, massive haemorrhagic pleural effusion, a left ovarian mass and an elevated C-125 marker. However, exploratory laparotomy, cytologic and histological examination of the pleural fluid and biopsied specimens revealed endometriosis. We present a case of intra and extra-pelvic endometriosis which simulated a malignant ovarian lesion and was histologically confirmed by cytology of the haemorrhagic pleural effusion and biopsy of the ovarian mass and peritoneal deposits obtained at laparotomy. This is to draw the attention of clinicians to endometriosis as a cause of pleural effusion, ascites and groin swelling which can simulate ovarian cancer.