Regressed Germ Cell Tumor : Microscopic
Microscopic Pathology: Regressed germ cell tumors (GCT) of the testis show circumscribed (seen here), stellate or irregular areas of scarring. The scarred areas contain hyalinized stroma with lymphoplasmacytic infiltrate, angiomatous foci, ghost tubules, siderophages, and coarse intratubular calcifications. The coarse, shard-like intratubular calcifications (see image 37) in scarred areas represent regressed intratubular embryonal carcinoma with comedonecrosis that has undergone dystrophic calcification. It is difficult to subtype the regressed GCT when there is complete scarring. The surrounding testicular parenchyma usually shows diffuse tubular atrophy and impaired spermatogenesis. Other findings include germ cell neoplasia-in-situ (65% of cases), Leydig cell clusters (40% of cases), tubular microliths (35% of cases), and necrosis.