1989 Volume 15 Issue 2 Pages 170-176
Ultrastructures of intracytoplasmic granules were studied in granular cell tumors arising from the tongue and back skin. The granules could be divided into 1) primary lysosomal granules, 2) secondary lysosomal granules, 3) multivesicular bodies, 4) myelin-like bodies. Ultrastructural and immunohistochemical results indicate that these granular cells are derived from Schwann cells. It is also suggested that there are metabolic disorders of myelin protein which cause lysosomal dysfunction in the granular cells, and that abundant vesicles in the multivesicular bodies may be related to the formation of both myelin-like and angular bodies. It is tentatively concluded that this lesion is a neoplastic hyperplasia of cells possessing a tendency of differ entiation to Schwann cells.
