Ultrastructure of the giant cell in de Quervain's subacute thyroiditis.

The author made an electron microscopic observation on multinucleated giant cells which appear in the thyroid gland in subacute thyroiditis (de Quervain). Numerous typical desmosomes, which intermingled with myriad of mitochondria and small electron dense granules, were found in the cytoplasm of giant cell. Desmosome is one peculiar to the intercellular junction of follicular epithelium of the thyroid gland, and the fact that many desmosomes were found in the cytoplasm is one of the proofs showing this giant cell to be possibly derived from the follicular epithelium.