A neoplasm that arises from the testis during childhood. The disease is MONDO_0037250 (childhood testicular neoplasm). Also known as: childhood neoplasm of testis, childhood neoplasm of the testis, neoplasm of testis of childhood, paediatric neoplasm of testis, paediatric neoplasm of the testis, paediatric testicular neoplasm, pediatric neoplasm of testis, pediatric neoplasm of the testis.