Specimens of cystadenolymphoma (Warthin's tumor) of salivary glands (parotid and submandibular glands) obtained from three patients were studied electron microscopically. The epithelial cells of the tumors contained numerous mitochondria, and the cristae of the large mitochondria were characteristic. The epithelial cells also contained crystalloids. The crystalloids were bounded by a single membrane and showed a periodic structure of 50 to 110Å. They were thought to be derived from Golgi apparatus.
