The occurrence of catecholamine neurons in a parietal lobe ganglioglioma.

A parietal lobe ganglioglioma in a 2-year-old girl was investigated ultrastructurally and immunohistochemically, using antiserum against tyrosine hydroxylase (TH), a rate-limiting enzyme of the catecholamine (CA)-synthesizing pathway. The tumor was composed essentially of neuronal and astrocytic cells. Ultrastructurally, numerous dense core vesicles measuring between 56 nm and 136 nm (mean, 90 nm) in diameter were observed in the neuronal cytoplasm and processes. The fact that the TH immunohistochemistry revealed many positive neuronal cells in the tumor tissue was of considerable interest. The implications and possible significance of the presence of CA neurons in this ganglioglioma are discussed.