Abstract
We report a case of primary penile undifferentiated sarcoma. A 16-year-old adolescent man visited Pusan National University Hospital complaining of a painless mass on his penis that was increasing in size. Magnetic resonance images revealed a 5×5-cm mass and pathological examinations revealed small round cell sarcomas with neuroendocrine differentiation. The tumor, which had metastatic pulmonary nodules, was treated by tumorectomy and systemic chemotherapy. Thirty-four months after the initial diagnosis, the patient was still alive without evidence of local recurrence or metastatic disease. This is our second case of an undifferentiated penile sarcoma.