Parathyroid Disease Flashcards
Where do the Parathyroid Glands come from embryologically?
3rd -4th brancheal pouches
inf from 3rd
sup from 4th
What are the cell tyes in the PT GLand?
Chief Cells (predominant, clear cytoplasm) Oxyphil cell (eosinophilic and larger)
What can be dertermined by a PTH assay?
Determine if Hypercalcemia is driven by Parathyroid or not
What are the systemic effects of PTH?
Increases serum Ca and decreases serum Phosphate
Bicarb reabsorption impaired in hyperPTH states
What are the most common causes of Hypercalcemia?
Hyperparathyroidism
Malignancy
What does VITAMINS TRAP stand for?
Vit A and D Immobilization Thyrotoxicosis Addison's disease Milk-alkali sy, Mult Myeloma, Mets Inflammatory disease Neoplasms Sarcoidosis
Thiazides/drugs
Rhabdomyelisis
AIDS
Paget’s Disease
What are the causes of Primary hyper PTH?
Single parathyroid adenoma 80%
Hyperplasia
Multiple Adenomas
PT cancer
What are the clinical features of Hyper PTH?
BONES- Long Bone pain
STONES- Kidneys, polyuria, polydipsia
GROANS (gastric ulcers)
MOANS (psychiatric, depression)
What are the lab findings in hyper PTH?
Inc Ca (mild) Dec serum phosphate Inc iPTH (innapropriately normal) Inc urine (>300 mg/24 hrs)
What is seen on X-ray in Primary Hyper PTH?
Loss of CORTICAL bone Subperiostial bone reabsorption Salt and Pepper Skull Osteitis fibrosa cystica Brown Tumors Renal Stones (nephrocalcinosis)
What is the Tx for Primary HyperPTH?
Surgical cure Experienced! ALL PTGs should be examined Resect an isolated adenoma PT hyperplasia (subtotal parathyroidectomy)
What are the common complications to PTG surgery?
Recurent Laryngeal nerve damage with hoarseness
Hypocalcemia- usually mild and transient
Hungry Bones syndrome
What are the medical Therapies for Hyper PTH?
Avoid Diuretics Adequate Hydration Estrogen Bisphosphonates Calcimimetics Monitor Serum Ca every 6 mon
What are the variants of Hyperparathyroidism?
Secondary- Vitamin D def, renal failure. Very Common
Tertiary- Continuous parathyroid stimulation
Familial Hypocalciuric Hypercalcemia- Inactivating mutation in Ca sensor/receptor
Asymptomatic
What are the causes of HYPO Parathyroidism?
Surgical Accidents
Infiltrative process(wilson’s, hemochromatosis)
Autoimmune destruction
Congenital- DiGeorge Synd-defective branchial arch synd
Dec Mg impairs PTH secretion and action
Familial
What are the clinical manifestations of Hypo PTH?
Depends on degree and rapidity of onset Paresthesia, spasm, tetany, laryngeal stridor, apathy, depression Ca of Basal ganglia on brain CT GI- N/V, pain, malabsorption Prolonged QT interval Cataracts Mucocutaneous Candidiasis
What are the systemic effects of Hypoparathyroidism?
Dec Mobilization of Ca Dec renal reabsorption of Ca Dec Renal Phos excretion Dec Renal prod of 1,25 diOHVitD Dec Ca and Inc Phos Dec PTH or inapporpriately normal
What else is on the Differential Diagnosis in HypoPTH?
Vit D resistance Vit D def Dec Ca mobilization from bone Osteoblastic Mets Inc tissue Ca Deposition CORRECT for SERUM ALBUMIN to confirm TRUE low Ca
What is the Tx of Hypocalemia?
1) IV Ca gluconate or PO calcium Carbonate
2) Vit D3
3) NATPARA (synthetic PTH analog)
What are the considerations in PTH resistance?
Type 1A (albright's Hereditary Osteodystrophy) Short Stature, short metacarpals Type 1B same labs but not Phenotype Pseudo Pseudo HypoPTH Same phenotype as pseudohypoPTH 1A but NO biochemical Abn These Pts are NOT deficient in PTH!
