脳梁原発類上皮腫の一例

Abstract

The authors report a case of epidermoid, primarily located in the corpus callosum, which revealed an usual CT finding, heterogeneous isodensity. Epidermoids are known to occur in the cerebellopontine angle and the parasellar region. A survey of previous literature confirms that this is the first reported case of an epidermoid whose primary site was the corpus callosum. A 55-year-old man was admitted to our clinic on May 25, 1987 because of a sudden onset vertigo attack. A CT scan of the patient revealed a lession of well circumscribed heterogeneous isodensity, interspread with areas of mixed low and nodular high density, which appeared to invade the right lateral ventricle and the pericallosal cistern. These are quite rare findings as epidermoids. Operative findings revealed that the primary site of the tumor was the corpus callosum and that the tumor was composed of a yellowish-white homogeneous waxy material, and suggested intratumoral hmorrhage. So the unusual CT finding of this case is interpreted along the following lines : The isodensity was attributed to the mixture of high dense blood and low dense components such as cholesterin, the areas of low density did not contain blood component, and the nudular high density was attributed to calcification.