Ganglioglioma containing osseous tissue and neurofibrillary tangles.

A ganglioglioma involving the temporoparietal lobe in a 49-year-old patient displayed several unusual histopathologic features. A large central focus of osseous tissue that was found may have resulted from metaplasia of a mesodermal component of the lesion. In addition, occasional ganglioma cells showed neurofibrillary tangles and granulovacuolar changes. The presence of these cytoplasmic structures, usually seen in Alzheimer's disease and other degenerative conditions, within a ganglioglioma emphasizes the diverse settings in which such neuronal changes may occur and may provide clues to their pathogenesis.