A case of adult granulosa cell tumor of the testis.

Background: Adult granulosa cell tumors of the testis (AGCTT) are classified as sex cord-stromal tumors. Only 31 cases have been reported. Typical presentation includes a slowly enlarging, painless testicular mass. Associated findings are gynecomastia, decreased libido, and erectile dysfunction. Immunohistochemistry can be used to confirm the diagnosis.

Case Report: A 22-year-old male presented with complaint of mild pain in both testicles. A testicular ultrasound revealed a 4.0×3.8×4.6 mm hypoechoic lesion within the left testicle. Serum tumor markers (STM) included lactate dehydrogenase (LDH) measuring 146 IU/L (98-192), serum alpha-1-fetoprotein (AFP), 2.89 ng/mL (0-9), and plasma beta human chorionic gonadotropin (Beta HCG) measuring less than 0.50 mIU/mL (<0.50-2.67). Computed tomography (CT) of the abdomen and pelvis with oral and intravenous contrast was normal. A radical orchiectomy was recommended but the patient refused. He agreed to surveillance with imaging and serum tumor markers (STM). The patient's testicular ultrasound showed the mass to be stable in size and STMs remained negative. The patient agreed to an orchiectomy 9 months after his diagnosis. This case is the first reported with c-kit-positive immunohistochemistry. His post-operative course has been unremarkable.

Conclusions: AGCTT is a rare tumor and information regarding its presentation, gross and microscopic morphology, and immunohistochemical characteristics is lacking. This report provides an update of the immunohistochemical findings and adds to the available data concerning this tumor. Based on the results of this case, future reports that include c-kit immunohistochemistry would be beneficial to evaluate its utility in diagnosing AGCTT.