title: Radiographic and neuro-SPECT imaging in an immature third ventricle teratoma: case report.
abstract: We report a case of an immature teratoma of the third ventricle, which was preoperatively thought to be a choroid plexus papilloma. The diagnosis was made by biopsy since the radiographic (CT, MRI), angiographic and scintigraphic findings ([99mTc]pertechnetate, 99mTc-DTPA, 99mTc-HMPAO brain SPECT) were nonspecific. Disruption of the blood-brain barrier is the mechanism for radionuclidic and contrast tumoral uptake and is demonstrated by marked contrast enhancement on CT and focal concentration on [99mTc]pertechnetate and 99mTc-DTPA images. No suppression of [99mTc]pertechnetate tumor uptake was observed following the administration of potassium perchlorate. Increased concentration of tumor protein is suggested by the increased signal on the T1-weighted magnetic resonance images and high [99mTc]pertechnetate uptake. The tumor's detection on the 99mTc-HMPAO brain SPECT was due to its intraventricular location. A number of potential mechanisms for brain tumor localization of 99mTc-HMPAO are discussed.
authors.affiliation: Department of Radiology/Nuclear Medicine, University of Missouri Hospital and Clinics, Columbia 65212.
authors.forename: E M
authors.initials: EM
authors.lastname: Cleto
authors.forename: R A
authors.initials: RA
authors.lastname: Holmes
authors.forename: A
authors.initials: A
authors.lastname: Singh
authors.forename: R
authors.initials: R
authors.lastname: Bierman
authors.forename: S
authors.initials: S
authors.lastname: Islam
authors.forename: T J
authors.initials: TJ
authors.lastname: Hoffman
mesh_terms: D002551:Cerebral Ventricle Neoplasms / Q000000981:diagnostic imaging*; D002648:Child; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D015609:Organotechnetium Compounds; D010091:Oximes; D019690:Technetium Tc 99m Exametazime; D016284:Technetium Tc 99m Pentetate; D013724:Teratoma / Q000000981:diagnostic imaging*; D015899:Tomography, Emission-Computed, Single-Photon; D014057:Tomography, X-Ray Computed
chemical_list: D015609:Organotechnetium Compounds; D010091:Oximes; D019690:Technetium Tc 99m Exametazime; D016284:Technetium Tc 99m Pentetate