A rare, benign, sex cord-stromal neoplasm, with a typically unilateral location in the ovary, characterized by mixed features of both fibroma and thecoma. Patients may be asymptomatic or may present with pelvic/abdominal pain and/or distension and, occasionally, with post-menopausal bleeding. Large tumors (>10cm) are often associated with pleural effusion and ascites (the Meigs syndrome triad).