Isolated Inhibin-Producing Granulosa Cell Tumor Causing Primary Amenorrhea: A Case Report

Juvenile granulosa cell tumors (JGCTs) are the most common pediatric ovarian sex cord-stromal tumor. Because most granulosa cell tumors are hormonally active, patients commonly present with signs and symptoms of endocrine dysfunction, including precocious puberty and menstrual irregularities. Most patients with JGCTs present with stage I disease confined to the ovary that can be managed with surgical excision alone with a favorable prognosis.

A 15-year-old girl presented with primary amenorrhea. Evaluation revealed suppressed follicle-stimulating hormone, elevated luteinizing hormone, normal estradiol, and a markedly elevated inhibin B, and pelvic ultrasound and magnetic resonance imaging showed a mildly enlarged right ovary with a 1.6-cm "ovarian follicle." After consultation with gynecologic oncology, the patient underwent right salpingo-oophorectomy with histopathologic findings consistent with JGCT. Menarche subsequently occurred 2 months after surgery.

Differences in GCT endocrine function, as well as the stage of pubertal development when the tumor develops, may lead to a variety of clinical presentations. It is important to consider inhibin-producing JGCT on the differential diagnosis for pediatric and adolescent patients presenting with amenorrhea.