Oncocytic variant of choroid plexus papilloma.
Two cases of oncocytic plexus papilloma are presented which were in the fourth ventricle and cerebello-pontine angle in women aged 70 and 63 years, respectively. The cytoplasm of the transformed tumor cells was enlarged, eosinophilic, and granular; and it was characterized ultrastructurally by innumerable mitochondria. Most of them had lamellar cristae, a clear matrix, and contained dense granules. These 'oncocytes' are identical with oncocytes of the human thyroid, parathyroid, bronchi, kidneys, adrenals, salivary gland and myocardium, and non-neoplastic choroid plexus epithelium. As far as we know, this is the first report of an oncocytic variant of the choroid plexus papilloma. Two unusual cases are described.
D000368:Aged; D002471:Cell Transformation, Neoplastic; D002551:Cerebral Ventricle Neoplasms / Q000473:pathology* / Q000648:ultrastructure; D002831:Choroid Plexus / Q000473:pathology / Q000648:ultrastructure; D004848:Epithelium / Q000473:pathology / Q000648:ultrastructure; D005260:Female; D006801:Humans; D008875:Middle Aged; D010212:Papilloma / Q000473:pathology* / Q000648:ultrastructure