In medicine, Meigs's syndrome, also Meigs syndrome or Demons–Meigs syndrome, is the triad of ascites, pleural effusion, and benign ovarian tumor (ovarian fibroma, fibrothecoma, Brenner tumour, and occasionally granulosa cell tumour). Meigs syndrome resolves after the resection of the tumor. [Source: Wikipedia ]

Ovarian fibrothecoma
OrphaNet reference
Ovarian fibrothecoma 
May Cause
T2-hyperintense adnexal mass
T2-hypointense adnexal mass