Extraovarian granulosa cell tumor

Area of Science:

• Gynecologic Oncology
• Pathology
• Endocrinology

Background:

• Granulosa cell tumors (GCTs) are rare ovarian neoplasms, but extraovarian GCTs are exceptionally uncommon.
• Extraovarian GCTs are hypothesized to arise from ectopic gonadal tissue along the embryonal path of the genital ridge.

Observation:

• A 58-year-old female presented with a large intraabdominal mass, with CT revealing a 15 cm retroperitoneal mass and an 8 cm mesenteric mass.
• The patient had a history of hysterectomy with bilateral salpingooophorectomy 20 years prior.
• Cytological and histopathological examinations confirmed adult-type GCT.

Findings:

• Immunohistochemical staining was crucial for diagnosis, showing positivity for inhibin and negativity for epithelial membrane antigen (EMA).
• These immunostains differentiated the GCT from potential metastatic epithelial tumors, particularly those from the ovary.
• Given the patient's history of oophorectomy and no prior GCT diagnosis, the tumor was classified as extraovarian.

Implications:

• Accurate diagnosis of extraovarian GCT requires excluding a prior history of ovarian GCT.
• Immunohistochemistry, specifically inhibin staining, is vital for confirming GCT and distinguishing it from other neoplasms.
• This case expands the understanding of rare GCT presentations and diagnostic challenges in post-oophorectomy patients.