[Testicular tumor in a 9-year-old boy].

A 9-year-old boy presented to the emergency department after noticing a painless mass on the right testicle during self-examination in the shower. On physical examination, both testes were mobile and painless, with the right testis twice as big as the left and exhibiting palpable resistance. Sonographic examination revealed a uniformly demarcated mass with a ventral protrusion on the right testis. Tumor markers and blood tests were normal. The testis was exposed inguinally and the tumor was enucleated, which revealed a dermoid cyst. The testicle could thus be preserved. Final histology confirmed complete excision of the benign dermoid cyst (mature teratoma). As testicular tumors in prepubertal boys are rare and usually benign, an organ-preserving procedure with perioperative biopsy should be aimed for. Due to the rarity of studies on recurrence after organ-preserving testicular surgery, we recommended regular ultrasound examinations during the first year after surgery, followed by annual examinations for a period of 5 years.