Neuroimage: giant intracranial lipoma with extracranial extension.

ation of the forehead lump. A large lobulated fat intensity nonenhancing mass was seen in the midline frontal region on T 1 and T 2 -weighted images ( fig. 2 , 3 ). The mass was hypointense on fat suppression T 2 and was seen intracranially in a dilated third and lateral ventricle, extending through the cribriform plate to become continuous with the subcutaneous fat through a large frontal bone defect ( fig. 4 ). Corpus callosum agenesis was seen. Lipomas are thought to occur from maldifferentiation of the meninx primitiva, a mesenchyme derivative of the neural crest with both ectodermal and mesodermal Dear Sir, Intracranial lipomas are rare tumors and account for less than 0.1% of the diagnosed brain tumors. Common sites of occurrence in the brain include the vicinity of the corpus callosum, though they have been reported in the interpeduncular, ambient as well as cerebellopontine cisterns [1] . A 36-year-old woman presented to the neurology outpatient department seeking evaluation for a lump on her forehead ( fig. 1 ). Though the lump had been present since birth, it had never bothered her and she had never consulted a physician. Cosmetic concerns due to her upcoming marriage had now prompted her to seek evaluReceived: August 8, 2007 Accepted: September 7, 2007 Published online: May 16, 2008