Answer: B

Histological Description: The testis shows a collection of dilated glands variably lined by respiratory epithelium or goblet cells. The glands are surrounded by smooth muscle and the glands lack cytological atypia. The surround testis shows normal spermatogenesis.

Discussion: Prior to 2013, all teratomas in the testis occurring in postpubertal males were considered malignant, even if histologically they appeared benign. Subsequently, it has been recognized that there exists benign teratomas termed Prepubertal-type teratomas, which although typically seen in prepubertal males can rarely also be seen postpubertally. The new term for malignant teratomas is Postpubertal-type teratomas, which is only seen in postpubertal males. Most postpubertal-type teratomas have more solid areas, cytological atypia, or lack the organoid architecture resembling normal GI or respiratory structures. However on occasion can mimic prepubertal-type teratomas. In addition in the surrounding testis of postpubertal-type teratomas there is typically atrophic seminiferous tubules with Sertoli only pattern and also more focally germ cell neoplasia in situ. Coarse calcifications are also occasionally seen. In contrast, the testis surrounding prepubertal-type teratomas is normal. Prepubertal-type teratomas also lack amplification of isochromosome 12p by FISH, which is seen in the vast majority of postpubertal-type teratomas similar to other malignant germ cell tumors. In the current case, the tumor lacked amplification of i12p.

Reference:
Zhang C, Berney DM, Hirsch MS, Cheng L, Ulbright TM. Evidence supporting the existence of benign teratomas of the postpubertal testis: a clinical, histopathologic, and molecular genetic analysis of 25 cases. Am J Surg Pathol. 201337(6):827-35.