Testicular epidermoid cysts are relatively rare benign testicular tumors that are primarily observed in young adults. Most testicular tumors in adults tend to be malignant, and high inguinal orchiectomy is often performed to treat testicular epidermoid cysts. However, accurate preoperative and intraoperative diagnoses can make testis-sparing surgery a viable option. A 25-year-old man presented with a painless mass in the right scrotum. Ultrasonography revealed a hypoechoic lesion with an echogenic rim and an onion ring sign. Magnetic resonance imaging showed the target sign in the right testis. These imaging findings are considered to be highly specific to testicular epidermoid cysts. Intraoperative rapid testicular frozen sections were also useful for performing testis-sparing surgery. For this patient, an accurate preoperative diagnosis and intraoperative pathological examination enabled testis-sparing surgery. (Hinyokika Kiyo 72 : 79-82, 2026 DOI : 10.17983/ActaUrolJap_72_2_79)
