Abstract
The C and oxyphil cells of the human thyroid are analyzed in the light of recent advances in cellular biology, cytochemistry, and histopathology. The C cell is present in the normal human thyroid, where its identification is cardinally by means of argyrophilic cytoplasmic granules. The morphology, topography and argyrophilia of C cells are discussed with reference to tumor, cyst, and teratoma formation in the thyroid gland. Oxyphii cells of the thyroid are cytochemically akin to C cells but arise from follicular cells. They occur in the thyroid and other protein-producing organs, but are themselves inefficient producers of proteins and glycoproteins. Speculation is made on their morphological characteristics, and consideration is given to DNA-RNA involvement in the functional and morphological alterations of this follicular cell type.