Gliofibroma originating from temporoparietal hamartoma-like lesions.

Clinical and neuropathologic observations are reported of a 16-year-old girl with a right temporoparietal tumor. The histologic picture revealed cortical areas with a peculiar growth of neurons, glia or tumor cells, and strands of collagen following the pattern of the cortical architecture. In this area of hamartoma-like cortex a large tumor nodule was found with anaplastic cells in fibrous stroma exhibiting partially positive GFAP reaction. The picture closely resembles the features of a tumor described in 1978 by Friede in the medulla oblongata of a 3-year and 9-month-old girl. A comparison of histology and ultrastructure of both tumors is followed by discussion of the origin of this peculiar type of tumor, focussing on the existence of unusually pluripotent cells that may develop into glial and mesenchymal cells.