CD34 and parathyroid gland adenoma: Although stromal (interstitial) cells of the parathyroid glands have been considered in some reports, mainly in vitro studies [36,37], TCs/CD34+ SCs have not been specifically explored in normal parathyroid glands, developing parathyroids, and most frequent parathyroid diseases, including hyperplastic parathyroids, currently classed as multiglandular parathyroid disease [38,39] and parathyroid adenoma.