Parathyroid

Parathyroid

·        Calcium metabolism:

·        Hyperparathyroidism:

o   Primary: ­PTH ® ­Ca₂+. 

§  Usually detected as incidental finding. If symptoms: pain/fracture, renal stones, constipation, abdominal pain, depression. Also maybe dehydration, ­BP, thirst, nocturia, stuff joints, myopathy

§  Associations: endocrine neoplasia (eg pancreas, pituitary, phaeochromocytoma and thyroid)

§  Causes: Single (90%) or multiple adenoma, carcinoma, hyperplasia 

§  Tests: ­Ca, ¯PO4 (unless renal failure), ­ALP, PTH raised or normal. CXR for „pepper pot skull‟ and pelvis

§  Treatment: surgery

o   PTH related protein (PTHrH): produced by some tumours – causes some of the hypercalcaemia seen in malignancy

o   Secondary Hyperparathyroidism: ¯Ca ® ­PTH. Causes: ¯Vitamin D and chronic renal failure (see 210 – complications of chronic renal failure)

o   Tertiary Hyperparathyroidism: continued secretion of PTH after prolonged secondary hyperPTH

·        Hypoparathryoidism:

o   Primary HypoPTH. Eg after neck surgery. ® ¯Ca and ­PO4, normal ALP. Associations with pernicious anaemia, Addison‟s, hypothyroidism, hypogonadism

o   PseudohypoPTH: Failure of target cell response to PTH. Round face, short metacarpals and metatarsals