[Ultrastructural study of adenolymphoma].

Ultrastructure of 10 adenolymphomas of parotid gland were studied. The neoplastic epithelium consists of "oncocytes" which are arranged in pseudostratified pattern. Their cytoplasm is almost totally packed with a large numbers of hypertrophic mitochondria showing a variety of peculiar forms. The amount and alteration of the mitochondria gradually increase in the order of pyramidal cell, common columnar cell and degenerated columnar cell. This might be a process of transposition representing degeneration due to metabolic disorder in the tumor. The obvious alterations of mitochondria are found in the cases with not only "hot" nodule but also "cold" nodule shown in the studies of 99mTc scintigraphy. There seems no relationship between "hot" nodule and alteration of mitochondria.