Part of “CHAPTER 48 – MORPHOLOGY OF THE PARATHYROID GLANDS“

The parathyroid glands are each surrounded by a thin connective tissue capsule that extends into the parenchyma, where fibrous septa divide the gland into lobules.1,4 The parenchymal cells of the parathyroid glands are arranged in cords, nests, or sheets around capillaries.1,4 Small clusters or spheres of cells are interspersed with foci of adipose tissue.

The adult parathyroid is composed of chief and oxyphil cells, a fibrous stroma, and variable amounts of fat (Fig. 48-1). The ratio of parenchymal to fat cells varies and probably is age dependent. Studies indicate that the formerly designated fat/cells ratio (50:50) may not reflect the normal state; in truth, normal parathyroid glands have only 17% fat.1,6,7,8 and 9