Oligodendroglioma with Granular Cells: A Case Report

Oligodendrogliomas can display a spectrum of histologic and ultrastructural features. The authors describe a case of an oligodendroglioma composed almost exclusively of eosinophilic granular cells. By electron microscopy, the tumor cells had abundant lysosomes containing electron-dense pleomorphic material. Although eosinophilic granular cells can be seen focally in oligodendrogliomas, it is unusual for them to pre-dominate. By light microscopy alone, such an appearance raises a broad differential diagnosis that electron microscopy can help resolve. In addition, the ultrastructural similarities between this tumor and granular cell tumors in general support the idea that granular cell neoplasms are a phenotype expressed by a wide variety of cells.