Ultrastructural study of mitochondria in oncocytes.

A number of mitochondria in oncocytes show pleomorphism by conventional electron microscopy. In an investigation of their stereostructure, specimens were obtained from 11 patients with Warthin's tumor, parts of which were used in the preparation of serial thin sections. It was revealed that cup-shaped and concentric ring forms of mitochondria resulted from invagination and that aberrant cristae such as the sheaflike and vesicular types were both derived from laminated cristae with vesicular structure.