Sandbox:ap

There are three types of hyperparathyroidism and should be differentiated between each other. Hyperparathyroidism should be differeniated from other causes of hypercalcemia. Causes of hypercalcemia include:

• Parathyroid related
  • Primary hyperparathyroidism
    • Typical primary hyperparathyroidism
    • Familial hypocalciuric hypercalcemia
  • Secondary hyperparathyroidism
  • Tertiary hyperparathyroidism
• Non-parathyroid related
  • Malignancy
    • Para-neoplastic syndrome: Parathyroid hormone related peptide
    • Hypercalcemia due to bone destruction
  • Medication induced
    • Thiazide diuretics
    • Lithium
  • Nutritional
    • Milk alkali syndrome
    • Vitamin D toxicity
  • Granulomatous disease
    • Sarcoidosis
  • Surgical
    • Immobilization

Hypercalcemia

Related to Parathyroid gland

Unrelated to parathyroid gland

Primary hyperparathyroidism

Secondary hyperparathyroidism

Tertiary hyperparathyroidism

Typical primary hyperparathyroidism

Familial hypocalciuric hypercalcemia

Malignancy

Medication induced

Nutritional

Granulomatous disease

Surgical

Para-neoplastic syndrome: Parathyroid hormone related peptide

Metaplasia: Hypercalcemia due to bone destruction

Thiazide diuretics

Lithium

Milk alkali syndrome

Vitamin D toxicity

Sarcoidosis

Immobilization

Differential diagnosis

Differential diagnosis fo hyperparathyroidism on the basis of hypercalcemia
Disorder		Mechanism of hypercalcemia	Clinical features	Laboratory findings	Imaging & diagnostic modalities
Hyperparathyroidism	Primary hyperparathyroidism	Increase in secretion of parathyroid hormone (PTH) from a primary process in parathyroid gland. Parathyroid hormone causes increase in serum calcium.	Usually asymptomatic Hypercalcemia detected on routine biochemical panel	↑ PTH ↑ Calcium ↓/N phosphate	Findings of bone resorption: X-ray DXA Preoperative localization of hyperfunctioning parathyroid gland: Non-Invasive Tc-99m sestamibi scintigraphy Neck ultrasound 4D-CT SPET(P-SPECT) PET MRI Invasive: Super sensitive venous sampling Selective arteriography Angiography Predicting post-operative success: Intraoperative parathyroid hormone monitoring
	Secondary hyperparathyroidism	Increase in secretion of parathyroid hormone (PTH) from a secondary process. Parathyroid hormone causes increase in serum calcium.	May present with history of: Chronic renal failure Vitamin D deficiency	↑ PTH ↓/N Calcium ↑ phosphate
	Tertiary hyperparathyroidism	Continuous elevation of parathyroid hormone (PTH) even after successful treatment of the secondary cause of elevated parathyroid hormone. Parathyroid hormone causes increase in serum calcium.	Usually present with history of: Kidney transplant Usually hyperplasia of all four parathyroid glands	↑ PTH ↑ Calcium ↑ phosphate
Malignancy	Para-neoplastic syndrome
	Hypercalcemia due to bone destruction
Medication induced	Lithium
	Thiazide diuretics
Nutritional	Milk-alkali syndrome
	Vitamin D toxicity
Granulomatous disease	Sarcoidosis