Electron microscopic and ultracytochemical investigations of thyroid C cells in primary hyperparathyroidism

The subject of study were C Cells of the human thyroid in course of primary hyperparathyroidism caused by the presence of a single adenoma. C cells were estimated by routine electron microscopic technique and by cytochemical cholinesterase (ChE) reaction according to Iwayama in electron microscopic technique. The presence of single C cells and of a small agglomeration of these cells, parafollicularily localized was found in the thyroid gland. An electron dense reaction product was noticed on membraneous structures of C cells of the thyroid.