Cryptorchidism and testis cancer. Atypical infantile germ cells followed by carcinoma in situ and invasive carcinoma in adulthood.

Atypical germ cells closely resembling carcinoma in situ (CIS) cells of the adult testis were found in a biopsy specimen from an undescended testis of a 10-year old prepubertal boy who was admitted for orchiopexy. The atypical cells were distributed as normal infantile germ cells in the seminiferous tubules, but in successive postpubertal biopsies an adult CIS pattern developed. Microspectrophotometric DNA measurements showed aneuploidy of both the prepubertal and postpubertal atypical germ cells, and the malignant potential of these cells was proven as small foci of invasive germ cell carcinoma in addition to widespread CIS were found when an orchiectomy was performed at the age of 20 years. Thus, premalignant changes in the testis may be found before puberty, and may precede a clinically detectable tumor by more than 10 years.