Benign glandular peripheral nerve sheath tumor of the seventh and eighth cranial nerve complex

A unique, deep-seated, benign, glandular peripheral nerve sheath tumor (PNS T) of the cerebellopontine angle is described. The tumor arose from the sev enth and eighth cranial nerve complex in a 15-year-old boy without neurofib romatosis. Histologically, benign glands were embedded in a bland spindle c ell stroma. The epithelial cells were immunoreactive for CAM 5.2, and focal ly for chromogranin. The spindle cells were positive for S100P. The benign glandular PNST unassociated with neurofibromatosis is a controversial entit y. The superficial location of most reported cases has made it difficult to exclude entrapped adnexae as a source for the glands. This tumor was separ ate from the internal auditory meatus on MRI scan, the most likely source o f entrapped glands at this site. This case is the first report of a deep-se ated, benign, glandular peripheral nerve sheath tumor. It suggests that gla ndular differentiation in PNSTs, while unusual, is not synonymous with neur ofibromatosis or malignancy.