Parathyroid Gland Pathology Flashcards

A set of vocabulary flashcards covering the anatomical, physiological, and pathological aspects of the parathyroid gland based on the lecture notes.

Chief cells

The majority of cells in the parathyroid gland, which contain prominent fat droplets and may transition into oxyphil or water clear cells.

Oxyphil cells

Cells in the parathyroid gland characterized by abundant granular eosinophilic cytoplasm, small pyknotic nuclei, and numerous mitochondria.

Water clear cells

Parathyroid cells that contain glycogen.

Parathyroid hormone (PTH)

A hormone whose secretion is triggered by decreased free (ionized) calcium levels ($Ca$) to increase calcium absorption from the GIT, mobilize calcium from bone, and increase renal excretion of phosphorus.

$$1,25-(OH)_2D_3$$

The active form of vitamin D whose synthesis is increased by PTH to enhance calcium absorption from the gastrointestinal tract.

Primary hyperparathyroidism

The autonomous hypersecretion of PTH, accounting for up to $90\%$ of cases of asymptomatic hypercalcemia, most commonly caused by adenomas.

Parathyroid adenoma

A highly cellular vascular encapsulated tumor, representing $80\%$ of primary hyperparathyroidism cases, often showing sheets of chief cells and a rim of normal parathyroid tissue.

Parathyroid hyperplasia

A diffuse or nodular unencapsulated growth affecting all four parathyroid glands, representing $15\%$ of primary hyperparathyroidism cases.

Parathyroid carcinoma

A rare cause of hyperparathyroidism ($< 5\%$) that is diagnosed based on local invasion and metastases.

Osteitis fibrosa cystica

A severe bone disease in hyperparathyroidism characterized by bone marrow containing increased fibrous tissue, foci of hemorrhage, and cyst formation.

Nephrolithiasis

The formation of urinary tract stones as a result of symptomatic primary hyperparathyroidism.

Nephrocalcinosis

The calcification of the renal interstitium and tubules.

Secondary hyperparathyroidism

Compensatory hypersecretion of PTH due to chronic hypocalcemia, often caused by renal failure and phosphate retention.

Tertiary hyperparathyroidism

A state of autonomous PTH hypersecretion that can develop from secondary hyperparathyroidism, even after correcting renal failure.

Hypoparathyroidism

A deficiency of PTH resulting in hypocalcemia and neuromuscular irritability, such as tetany and carpopedal spasm.

DiGeorge syndrome

A condition characterized by congenital parathyroid agenesis leading to hypoparathyroidism.

AIRE gene

The auto-immune regulator gene; mutations in this gene cause familial hypoparathyroidism.

Pseudohypoparathyroidism

A condition resulting in hypocalcemia and hyperphosphatemia despite increased serum levels of PTH, caused by end-organ resistance.

GNAS1 gene

The gene that, when mutated, causes end-organ resistance in kidneys and bones to PTH stimulation, leading to pseudohypoparathyroidism.