Interstitial cell tumour and germ cell tumour with carcinoma in situ in rabbit testes.

Simultaneous occurrence of a well-demarcated interstitial cell tumour and an intratubular seminoma-like tumour, which was beginning to invade peritubular areas, in the contralateral testes of a 3-year-old Dutch-Belted rabbit is described. Morphological hallmarks of carcinoma in situ, which have not been reported previously for the rabbit, were observed in association with the seminoma. These observations indicate that carcinoma in situ, preceding a seminoma-like tumour, occurs in the rabbit and that the rabbit may serve as a practically useful animal model for studying testicular germ cell neoplasia.