抄録
The light microscopic, electron microscopic and immunohistochemical features of a large cell undifferentiated parotid gland carcinoma are presented. The tumor was composed predominantly of undifferentiated, polygonal large cells with focally admixed malignant oncocytic cells. The presence of carcinoembryonic antigen, lactoferrin, lysozyme and secretory component in the oncocytic tumor cells was found immunohistochemically, whearas no immunoreactivity with the tested biological markers was observed in undifferentiated polygonal large cells. Ultrastructurally, numerous mitochondria with crescent-shaped cristae were packed in the tumor cells within the oncocytic cell areas, and junctional complexes between the neighboring cells represented contiguous tight junctions and distinct desmosomes in the area of undifferentiated cells.
