Parathyroid Pathology- LM Flashcards
What are the 2 types of parathyroid cells.
One is more pink, which one?
Which one secretes PTH
chief cells- purplish-PTH producing
oxyphil cells PINK
Who want to talk through the various effects of PTH on the body?
What is the cause of primary hyperparathyroidism?
Primary hyperparathyroidism: an autonomous overproduction of parathyroid hormone (PTH), usually resulting from an adenoma or hyperplasia of parathyroid tissue
What is secondary parathyroidism caused by?
Secondary hyperparathyroidism: compensatory hypersecretion of PTH in response to prolonged hypocalcemia, most commonly from chronic renal failure.
What is tertiary Hyperparathyroidism cause by?
Tertiary hyperparathyroidism: persistent hypersecretion of PTH even after the cause of prolonged hypocalcemia is corrected, for example after renal transplant
What are the types and % occurrance of endocrine disorders causing hyperparathyroidism?
Adenoma: 85% to 95%
Primary hyperplasia (diffuse or nodular): 5% to 10%
Parathyroid carcinoma: ~1%
What is a sestamibi scan?
How would and adenoma look different from hyperplasia on the scan?
a technitium radionucleotide is given and uptake is measured at the parathyroid glands.
Adenoma would most likely only have uptake in one place as opposed to mult places.
WHat should you always see in a normal parathyroid gland?
Fat
The picture show the rim of the normal tissue with an adenoma above.
WHat characteristic finding on histology of the bone would be present in hyperparathyroid disease?
Railroad tracking from osteoclast burrowing into the bone.
ALso called disected osteitis.
How are most cases of primary HPT discovered?
What age group?
As many as 80% of patients with this condition are identified in the outpatient setting, when hypercalcemia is discovered incidentally on a serum electrolyte panel. Most cases occur in the 50s or later in life.
The most common cause of primary hyperparathyroidism is a solitary parathyroid adenoma arising
Sporadically
Familial syndromes are a distant second to sporadic adenomas as causes of primary hyperparathyroidism. WHat are the mutation present?
Multiple Endocrine Neoplasia, types 1 and 2, caused by germline mutations of MEN1 and RET, respectively
Symptomatic, untreated primary hyperparathyroidism manifests with three interrelated skeletal abnormalities: What are they?
1.Osteoporosis- DUH
For unknown reasons, the increased osteoclast activity in hyperparathyroidism affects cortical bone (subperiosteal and endosteal surfaces) more severely than medullary bone.
- Brown spots
- osteitis fibrosa cystica (von Recklinghausen disease of bone).
How are brown tumors formed?
The bone loss predisposes to microfractures and secondary hemorrhages that elicit an influx of macrophages and an ingrowth of reparative fibrous tissue, creating a mass of reactive tissue, known as a brown tumor. The brown color is the result of the vascularity, hemorrhage, and hemosiderin deposition, and it is not uncommon for the lesions to undergo cystic degeneration.
WHat is osteitis fibrosa cystica (von Recklinghausen disease of bone).
The combination of increased osteoclast activity, peritrabecular fibrosis, and cystic brown tumors is the hallmark of severe hyperparathyroidism
You thought you were done, there is one more biggy that you should know?
Hint: Ca+2
Kidney stones, no wait, stones, yep stones.
PTH-induced hypercalcemia favors formation of urinary tract stones (nephrolithiasis) as well as calcification of the renal interstitium and tubules (nephrocalcinosis). Metastatic calcification secondary to hypercalcemia may also be seen in other sites, including the stomach, lungs, myocardium, and blood vessels.
Discuss as a group what the PTH and Calcium levels would be for malignancy and hyperparathyroidism?
See how many causes of hypercalcemia you can get, a piece of candy to anyone who can get more than 4?
Most people that have PT ademonas are asymptomatic, BUT what is the pneumonic for symptomatic people?
We talked about renal failure being the main cause of secondary HPT, what are some other causes?
Although several other diseases, including inadequate dietary intake of calcium, steatorrhea, and vitamin D deficiency, may also cause this disorder
What is the clinical course of secondary HPT?
What is the prognosis?
Basically the same as primary but dominated by the renal failure and not as severe.
Calcifications of heart, lung, stomach, blood vessels - pH changes
Can regress with control.
WHat is calciphylaxis?
The vascular calcification associated with secondary hyperparathyroidism may occasionally result in significant ischemic damage to skin and other organs,
How are pt with secondary HPT treated
Patients with secondary hyperparathyroidism often respond to dietary vitamin D supplementation, as well as phosphate binders, which decrease the prevailing hyperphosphatemia.
WHat is tertiary HPT?
How would you treat?
parathyroid activity may become autonomous and excessive, with resultant hypercalcemia,
Parathyroidectomy may be necessary to control the hyperparathyroidism in such patients.
