title: A 6-year-old girl with an extra-axial mass in the middle cranial fossa.
abstract: A 6-year-old Japanese girl presented with psychomotor seizures. Magnetic resonance (MR) images disclosed a mass lesion in the left middle cranial fossa with an internal irregular-shaped area, which was hyperintense on T1-weighted images and hypointense on T2-weighted images. Gross total resection of the tumor was performed through left occipital craniotomy. The tumor was white-to-grayish hard tissue, focally showing blackish pigmentation. Histological, immunohistochemical and electron-microscopical analyses revealed that white-to-grayish hard tissue corresponded to an atypical meningioma, and the blackish pigmentation of the tumor was composed of non-neoplastic, reactive hyperplasia and colonization of meningeal melanocytes in the meningioma tissue. A meningioma with reactive hyperplasia and colonization of meningeal melanocytes is unusual, but it is clinically important to differentiate this entity from other melanocytic tumors.
authors.forename: Kenta
authors.initials: K
authors.lastname: Masui
authors.forename: Satoshi O
authors.initials: SO
authors.lastname: Suzuki
authors.forename: Akira
authors.initials: A
authors.lastname: Kondo
authors.forename: Toru
authors.initials: T
authors.lastname: Iwaki
mesh_terms: D002648:Child; D035301:Cranial Fossa, Middle / Q000473:pathology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008279:Magnetic Resonance Imaging; D008544:Melanocytes / Q000473:pathology; D008578:Meninges / Q000473:pathology; D008579:Meningioma / Q000473:pathology*; D008854:Microscopy, Electron; D012640:Seizures / Q000209:etiology; D019292:Skull Base Neoplasms / Q000473:pathology*