Intranuclear membranous profiles in germinoma cells--a variant of nuclear pockets and intranuclear annulate lamellae.
When ultrastructurally examining 24 germinomas comprising 12 seminomas, 4 dysgerminomas, 1 mediastinal germinoma, and 7 intracranial germinomas, intranuclear membranous profiles were noticed in 17 germinomas, ranging from 20-100 nm in width and 3 microns in length. With occasional connections to the nuclear envelope through a small hole, intranuclear membranous profiles in germinoma cells were considered as clefts of the nuclear envelope. While most frequently situated under the inner nuclear membrane, they varied in configuration as well as distribution. As sequestered round mass of nuclear material, they were a variant of nuclear pockets containing nucleoplasm. Intranuclear annulate lamellae were occasionally present apart from the nuclear envelope and connected with nuclear clefts. Eleven of the twelve seminomas and 6 of the twelve non-seminomatous germinomas showed intranuclear membranous profiles, and the incidence of such profiles was much higher in seminomas than in non-seminomatous germinomas. Intranuclear membranous profiles facing the inner nuclear membrane were also noted in spermatogonia in adolescents and adults. It was suggested that intranuclear membranous profiles in germinoma cells could be structures following ones occasionally seen in spermatogonia.
D000293:Adolescent; D000328:Adult; D001932:Brain Neoplasms / Q000648:ultrastructure; D002648:Child; D004407:Dysgerminoma / Q000648:ultrastructure*; D005260:Female; D006801:Humans; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged; D009685:Nuclear Envelope / Q000648:ultrastructure*