Altered serous granules in acinar cells of a human parotid gland

A peculiar alteration of secretory granule morphology was observed in serous cells of the parotid gland from a patient undergoing radical neck surgery for oral cancer. The granules were half filled with a dense material that in early stages of formation appeared to consist of filaments or fine tubules. Growth of these apparently rigid fibrillar structures caused the formation of long pseudopodia on the granule surface. Granule alterations were not due to preoperative treatment because the patient had had none. It is postulated that the granule alterations were due to a perturbation in granule composition, possibly because of a genetic mutation that led to changes in one or more of the proline-rich proteins that normally reside in parotid serous granules.