Paraganglioma of the thyroid gland.

A case of a paraganglioma located within the thyroid gland is reported, and the light- and electron-microscopic features are described. Review of the literature reveals only one other case of intrathyroidal paraganglioma, which was associated with bilateral carotid body tumors. Regarding the present case, no similar tumors have been noted elsewhere. The findings support the view that the thyroid gland should be included among the unusual sites at which primary paragangliomas may occur.