title: Oncocytic choroid plexus carcinoma: case report.
abstract: Herein, we report an unusual choroid plexus carcinoma with extensive oncocytic transformation. A 13-month-old girl presented with acute lethargy which quickly progressed to coma. A CT scan of the head revealed impending herniation due to hemorrhage within an intracranial tumor. An MRI scan showed a large, partly cystic and highly vascular left lateral ventricular mass. A near total resection was achieved. Microsections revealed a WHO Grade III choroid plexus carcinoma with extensive oncocyti c transformation. A minor portion of the moderately to poorly differentiated tumor exhibited classical microscopic features of choroid plexus carcinoma, including marked nuclear atypia, brisk mitotic activity (78/10 HPF), a high MIB-1 labeling index (44%) and zones of necrosis. In contrast, the large, eosinophilic, cytologically malignant but granular-appearing oncocytes comprising the majority of the lesion showed scant (1/10 HPF) mitotic activity and only a low MIB-1 labeling index (5%). A subsequent recurrence at 1 year consisted entirely of non-oncocytic tumor. Choroid plexus carcinoma with oncocytic transformation has not been previously reported. The remarkable extent of this alteration and its clinical significance remains to be determined.
authors.affiliation: Department of Pathology, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: A
authors.initials: A
authors.lastname: Sav
authors.forename: B W
authors.initials: BW
authors.lastname: Scheithauer
authors.forename: C A
authors.initials: CA
authors.lastname: Mazzola
authors.forename: S R P
authors.initials: SR
authors.lastname: Ketterling
authors.forename: S J
authors.initials: SJ
authors.lastname: Thompson
authors.forename: M H
authors.initials: MH
authors.lastname: Reilly
mesh_terms: D018249:Adenoma, Oxyphilic / Q000473:pathology*; D001921:Brain / Q000378:metabolism / Q000473:pathology*; D002277:Carcinoma / Q000378:metabolism / Q000473:pathology* / Q000628:therapy; D016545:Choroid Plexus Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000628:therapy; D005190:Family; D005260:Female; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D024862:Oxyphil Cells / Q000378:metabolism / Q000473:pathology; D014057:Tomography, X-Ray Computed