A Granulosa Cell Tumor Lacking FOXL2 Mutation With 12-year-old Onset and Adult Presentation

Abstract

Synopsis: Granulosa cell tumors (GCTs) are rare, sex cord-stromal tumors classified as adult or juvenile types. Juvenile-type GCT typically occurs in children and adolescents and rarely recurs after a long, disease-free interval. Recurrence beyond two decades is extremely rare. A 40-year-old woman (G5P3), with a history of left oophorectomy at age 12 for an ovarian tumor, was referred to our hospital for further evaluation of a right ovarian mass diagnosed as a mature teratoma 1 year earlier. Transvaginal ultrasound revealed a 45-mm right adnexal mass, which had gradually increased in size. Magnetic resonance imaging revealed a 55-mm right adnexal tumor with diffusion restriction and a 15-mm soft tissue lesion in the left pelvis, raising suspicion for malignancy. Surgery was performed. Intraoperatively, the tumor was located in the posterior leaf of the right broad ligament, adherent to the right ovary and uterosacral ligament. Frozen section diagnosis confirmed malignancy; therefore, a total abdominal hysterectomy, right salpingo-oophorectomy, and omentectomy were performed. Histologically, the tumor showed features characteristic of adult-type GCT, including Call-Exner bodies and coffee-bean–like nuclei. We obtained pathological slides from her initial surgery at age 12 from the previous hospital, which had been diagnosed as juvenile-type GCT. Genetic testing for the FOXL2 mutation was negative in both the current and previous specimens. Considering the patient's clinical history, absence of FOXL2 mutation, and histologic comparison, the current tumor was diagnosed as an adult-type GCT.