title: Primary intracranial germinoma involving the midbrain.
abstract: To our knowledge, this is the first reported case of a germinoma involving the midbrain without the demonstrable coexistence of any common midline tumors. A 27-year-old man was referred to our institution for evaluation and treatment of diplopia persisting for 5 years. Magnetic resonance imaging (MRI) showed the mass in the midbrain to be of iso intensity on T1-weighted images, and of high intensity on T2-weighted images with homogeneous enhancement. MRI-guided stereotactic biopsy was performed, and the histologic diagnosis was germinoma. Following biopsy, external beam radiotherapy of 50 Gy (whole brain 30 Gy: local 20 Gy) was performed. At the time of discharge, the patient's neurological symptoms had resolved. Follow-up MRI revealed disappearance of the tumor. These findings suggest the diagnostic value of magnetic resonance image-guided stereotactic biopsy in the differential diagnosis of adult brainstem lesions, which should now include germinoma.
authors.affiliation: Department of Neurological Surgery, Okayama University Medical School, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Matsumoto
authors.forename: A
authors.initials: A
authors.lastname: Tabuchi
authors.forename: N
authors.initials: N
authors.lastname: Tamesa
authors.forename: H
authors.initials: H
authors.lastname: Nakashima
authors.forename: T
authors.initials: T
authors.lastname: Ohmoto
mesh_terms: D000328:Adult; D001707:Biopsy, Needle / Q000379:methods; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000532:radiotherapy; D003937:Diagnosis, Differential; D018237:Germinoma / Q000175:diagnosis* / Q000532:radiotherapy; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008636:Mesencephalon; D013238:Stereotaxic Techniques; D016896:Treatment Outcome