Malignant Warthin's tumour: an ultrastructural study.

Undifferentiated malignant cells in a Warthin's tumour (adenolymphoma) were studied by light and electron microscopy. The ultrastructure of these cells indicated that they were poorly differentiated adenocarcinoma arising from the glandular component of the Warthin's tumour. Some differences between this case and previous ultrastructural studies are described.