Post-pubertal Teratoma

Comments:
In post-pubertal teratomas, the surrounding testis is often atrophic and shows germ cell neoplasia-in-situ (GCNIS), hypospermatogenesis and microlithiasis. In mixed germ cell tumors, teratoma usually coexists with yolk sac tumor or embryonal carcinoma.

This image from a post-pubertal teratoma shows GCNIS with pagetoid involvement of rete testis.