Pathology of the Parathyroid Flashcards
normal weight of parathyroid
25-50mg each
there are 4 of them
color of parathyroid
yellowish
has fat
more fat with age
cells of parathyroid
chief cells
oxyphil cells - more red - more mito
function of PTH
increase renal tubular reabsorption of calcium
increase conversion of vit D
urinary phosphate excretion
GI calcium absorption
primary hyperparathyroidism
adenoma or hyperplasia of parathyroid tissue
secondary hyperparathyroidism
chronic renal failure
compensatory hypersecretion of PTH in response to prolonged hypocalcemia
tertiary hyperparathyroidism
renal transplant
persistant hypersecretion of PTH even after cause of prolonged hypocalcemia is corrected
most common cause of primary hyperparathyroidism
adenoma - 85%
primary hyperplasia - diffuse or nodular 5-10%
parathyroid carcinoma 1%
52yo F elevated Ca on medical profile
sestamibi scan shows hot nodule
parathyroid adenoma
calcitonin scan
sestamibi
-technetium scan
primary hyperplasia vs. adenoma
adenoma - glands outside adenoma are shrunken - feedback inhibiion
most common identification of primary hyperparathyroidism
incidental on serum electrolyte panel - see hypercalcemia
genetic parathyroid adenomas
MEN 1 - MEN1 mutation
MEN 2 - RET mutation
primary hyperparathyroidism physiologic changes
skeletal system - osteoporosis, brown tumors, osteitis fibrosa cystica
urinary tract - nephrolithiasis
skeletal changes hyperparathyroidism
osteoporosis - phalanges, vertebra, femur - cortical bone affected most
medullary bone - osteoclast tunnel - railroad track appearance - dissecting osteitis
railroad track appearance
of bones
hyperparathyroidism
dissecting osteitis
brown tumor
bone loss in hyperparathyroidism - microfractures - influx of macrophages and fibrous tissue
hemosiderin deposition
von recklinghausen disease of bone
osteitis fibrosa cystica
combo of increased osteoclast activity, peritrabecular fibrosis, cystic brown tumors
severe hyperparathyroidism**
urinary tract and hyperparathyroidism
urinary tract stone formation - nephrolithiasis
also calcification of renal interstitium and tubules
most common cause of asymptomatic hypercalcemia
primary hyperparathyroidism
most frequent cause of symptomatic hypercalcemia in adults
malignancy
multiple myeloma
secretion of PTH-rP
-PTH related peptide
high calcium and low PTH
high calcium of malignancy
multiple myeloma and others
primary hyperparathyroidism associations
painful bones
renal stones
abdominal groans
psychic moans
enlargement of all 4 parathyroid glands
secondary hyperparathyroidism
-hyperplasia
most commonly - with renal failure
patients with secondary hyperparathyroidism
dietary vit D supps
phosphate binders
tx tertiary hyperparathyroidism
minority of patients - becomes excessive hyperparathyroid
parathyroidectomy to control hyperparathyroidism
common cause of hypoparathyroidism
consequence of surgery
during thyroidectomy
autoimmune hypoparathyroid
mutations in AIRE
childhood onset of candidiasis
several years later hypoparathyroidism
adolescence adrenal insufficiency
auto-dom hypoparathyroidism
GOF in SACR gene
hypocalcemia and hypercalciuria
familial isolated hypoparathyroidism
FIH - rare
auto dom - mutation in PTH precursor peptide
auto rec - LOF function in GCM2 - essential for parathyroid development
congenital absence of parathyroid
with other malformations
thymic aplasia
cardiovascular defects
22q11 deletion syndrome
chvostek sign
tapping facial nerve - induce contraction of muscles of eye, mouth, nose
hypocalcemia**
trousseau sign
carpal spasms - with occlusion of forearm circulation
hypocalcemia
hypocalcemia
tetany - neuromuscular irritability
deceased serum calcium levels
clinical of hypoparathyroidism
mental status changes
intracranial manifestations - parkinsonian like movement disorders
ocular disease - lens and cataracts - calcification
cardiovascular manifestations - prolonged QT interval
dental abnormalities
pseudohypoparathyroidism
end organ resistance to PTH action
hypocalcemia, hyperphosphatemia, elevated circulating PTH
short stature, mental retardation, short 4th and 5th fingers
