Intracranial nonspecific inflammatory granuloma.

A case of nonspecific inflammatory granuloma arising from the dura mater near the hypoglossal canal is reported. A 38-year-old woman developed an isolated left hypoglossal nerve palsy. Computed tomography and magnetic resonance imaging demonstrated an enhanced tumorous lesion at the inner orifice of the left hypoglossal canal. Skull x-ray was normal, and cerebral angiography showed no vascular abnormalities. Examination of the cerebrospinal fluid showed mild pleocytosis with a predominance of lymphocytes. Systemic examination revealed no abnormalities. The tumor was removed completely and pathologic investigation revealed that it was an inflammatory granuloma. The patient's history and laboratory data, however, failed to suggest the underlying disease, and histopathologic examination did not indicate any special type of granuloma. Therefore, the lesion was diagnosed as a nonspecific inflammatory granuloma.