Hyper Parathyroidism - HPT Flashcards
Hyper parathyroidism is a result of
increased blood level of parathyroid hormone
Explain Primary HPT
- what causes it
- Is it a major cause of hypercalcimia
Involves the gland itself
Stimulated to secrete more parathyroid hormone
Most commonly a benign adenoma, carcinoma, hyperplasia, ectopic tumors, hyper CA and hypophosphatemia
Explain Secondary HPT
Abnormal stimulation of the glands by sustained HYPOCALCEMIA predominantly from renal disease - loss of Ca++ and decrease in Vit. D - low normal hypocalcemia and hyperphosphatemia Can be caused by: -Chronic renal disease - malabsorption - serum calcium is low or low normal - Phosphorous is elevated - associated with renal osteodystrophy
What occurs in renal osteodystrophy
Elected phosphorous can lead to soft tissue calficiation - which can even lead to bone osteosclerosis
Explain Tertiary HPT
Long standing secondary HPT with chronic renal failure or malabsorption
Parathyroid function may become autonomous - can relate to ectopic tissues
paraneoplastic syndrome
May have hypercalcemia
Only been around for 20 years
What is the function of parathyroid hormone
Increase in osteoclastic and osteocytic stimulation
- Ca++, phosphorus and osteoid are all broken down
Osteoblastic inhibition
Renal conversion of calcium an dinhbition of phosphate resorption
Renal stimulation of 1-alpha-hydroxylase, causing increased formation of 1, 25 Vit D
Indirect efect on GI absorption
Once Ca++ serum goes down the parathyroid starts to stimulate parathyroid hormone - tells the osteoclasts and osteocytes to get to work and work harder - the renal will start to dump ca++ because kindle can not conserve ca+ - excessive parathyroid stimulation will ultimately have us
loose bone density
Calcitonin is secreted by
the human thyroid - c cells or parafolicular cells
Calcitonin is regulated by
serum calcium level
Calcitonin inhbits
bone resorption by osteoclastic function and may lead to hypocalcemia and hypophosphatemia
Inhibits GI calcium absorption
Stimulates osteoblastic activity
Inhibits renal tubular cells reabsorption of calcium
Why is calcitonin important in humans?
is the normal regulation of normal calcium homeostasis
Histopathic changes in HPT include…
What are common disease names related?
osteoclastic and osteocytic bone resorption with fibrous tissue replacement
Osteitis fibrosa cystica
Recklinghausen’s disease of bone
Major bone changes in HPT include
Osteopenia
accented trabecular pattern
loss of cortical definition
Brown tumors
What bone change is unique to HPT? Explain it
Brown tumors: Subperiosteal bone resorption
What is the male and female ratio for HPT? What age range?
Female 3: 1 males - 30 - 50 years old
Symptoms of HPT usually related to what three structures?
Bone, renal, GI
Symptoms/signs of HPT include
weakness (hypercalcemia), lethargy, polydipsia, pyuria, renal calculi (kidney stones), bone tenderness
Sub-periosteal bone resorption
Where in the body is it common to see Tertiary HPT
In the hands
Middle phalanges radial aspect (thumb) 2nd - 4th digits pathognomonic
Where does inter cortical bone resorption occur?
within haversian canals, linear striations/porous looking
Where does endosteal bone resorption occur?
Typically hand and with other findings
Where does subchondral bone resorption occur?
Common in SI, SC, AD, symphysis pubis and disco vertebral junctions - can mimic inflammatory joint disease
ex) SI joint sacrolilits
Tertiary HPT are against
Joints - they get up under the articulation
DRA stands for
Dialysis related athropathy
DRSA means
Dialysis related spondyloarthropathy
What does the trabecular bone resorption look like in tertiary HPT?
Diffuse in skeleton, very prominent in cranium - cause very granular appearance to diploid space - salt and pepper skull
Sub-ligamentous bone resorption at enthuses can occur in terry HPT this can happen at the sites of:
Trochanters, ischial and humeral tuberosity, elbow, calcaneus, inferior distal end of clavicle
Explain Brown tumor/osteoclastoma
Localized cyst-like bone resorption containing fibrous tissue, giant cells and hemorrhage “brown” color is histopahtoligc * tumor like disorder
Acro osteolysis
Distal tuft resorption, seen with many other conditions - all RA, psoriatic arthritis, scleroderma, burn/frostbie victims, gout
Densities might find HPT T/F
True
Chondrocalcinosis
Calcification of articular cartilage - maybe hydroxyapatite or CPPD (calcium pyrophosphate dehydrate)
Rugger-Jerse Spine may be related to ______. And is found in which type of HPT
Hyperphosphatemia
Secondary
Osteosclerosis and periostitis is most commonly founding what HPT and rarely in what HPT?
Commonly found in secondary
Rarely found in primary
Chondrocalcinosis and brown tumors are most commonly found in what HPT and rarely in what HPT?
More commonly founding primary
Rarely found in secondary
Combination of secondary HPT + osteomalacia + soft tissue and vascular calcification is termed
Renal osteodystrophy/uremic osteopathy
PHP
- Etiology
- define
- characteristics
- X-ray findings
Genetic disorder
Related to end organ resistance to parathyroid hormone with normal Ph production
Characteristics: short stature, obesity, round face, brachydactyl,
Xray: similar to hypoparathyroidism, hypocalcemia and hyperphosphatemia
*have it but do not respond to it
PPHP
- etiology
- what makes it different from PHP
genetic
Similar to PHP
has normal Ca++ and phosphorous
Hypoparathyroidism
Defieicniy of PTH most commonly from excision or trauma to the PTG during thyroidectomicies - seen in
Signs of hypoparathyroidism?
Bone osteosclerosis thickening of the cranial vault bones calcification of the basal ganglia rarely choroid plexus and cerebellum Rare spine changes: pain, stiffness with calcification of ALL and posterior spinal ligaments - resembling DISH
Etiology of Hypoparathyroidism
Acquired
Neoplasm in children is most likely
Leukemia
Neoplasm in adults is most likely
Non-Hodgkins
T/F neoplasm is often seen with anemia
True
