Telocytes/CD34+ Stromal Cells in the Normal, Hyperplastic, and Adenomatous Human Parathyroid Glands.
Date
2023Abstract
Telocytes/CD34+ stromal cells (TCs/CD34+ SCs) have been studied in numerous organs
and tissues, but their presence and characteristics in the parathyroid glands have not been explored.
Using immunological and ultrastructural procedures, we assess the location, arrangement, and
behavior of TCs/CD34+ SCs in normal human parathyroids, during their development and in their
most frequent pathologic conditions. In normal parathyroids, TCs/CD34+ SCs show a small somatic
body and long thin processes with a moniliform aspect, form labyrinthine systems, connect other
neighboring TCs/CD34+ SCs, vessels, adipocytes, and parenchymal cells directly or by extracellular
vesicles, and associate with collagen I. TCs/CD34+ SCs and collagen I are absent around vessels and
adipocytes within parenchymal clusters. In developing parathyroids, TCs/CD34+ SC surround small
parenchymal nests and adipocytes. In hyperplastic parathyroids, TCs/CD34+ SCs are prominent
in some thickened internodular septa and surround small extraglandular parenchymal cell nests.
TCs/CD34+ SCs are present in delimiting regions with compressed parathyroids and their capsule in
adenomas but absent in most adenomatous tissue. In conclusion, TCs/CD34+ SCs are an important
cellular component in the human parathyroid stroma, except around vessels within parenchymal
nests. They show typical characteristics, including those of connecting cells, are present in developing
parathyroids, and participate in the most frequent parathyroid pathology, including hyperplastic and
adenomatous parathyroids.