Inhibin B Secreting Ovarian Fibroma

Nearly 90% of all the hormone-producing ovarian tumours are sex cord-stromal tumours (SCSTs). The Ovarian fibroma is a hormonally inactive variant of SCST. It is composed of spindle, oval, round cells producing collagen and accounts for approximately 4% of all ovarian neoplasms. Amongst the other SCSTs, Inhibin B is an important tumour marker. It is a heterodimeric glycoprotein hormone that is secreted primarily by the granulosa cells of the developing follicles. High levels of Inhibin-B can hamper follicular recruitment, leading to amenorrhea in a reproductive age woman.

In this case report, we describe a rare case of a reproductive age female presenting with secondary amenorrhea, having an Ovarian Fibroma, producing massive amounts of Inhibin B.

Although some pathological variants of ovarian fibromas like cyst-adeno-fibroma and ovarian fibro-thecoma are known to secrete inhibin B, benign /pure ovarian fibromas rarely do so.