Hypercalcemia: Difference between revisions

Content deleted Content added

VisualWikitext

Inline

Latest revision as of 21:16, 2 March 2026

Background

Pathophysiology

Vitamin D is absorbed from GI tract
- First hydroxylation to 25-OH vitamin D in liver
- Second hydroxylation to 1,2-OH vitamin D in kidneys by alpha-1 hydroxylase
PTH from parathyroid glands
Calcitriol is involved somewhere

Differential Diagnosis

High PTH
- Primary hyperparathyroidism
  - Parathyroid adenoma (most common)
- Tertiary hyperparathyroidism
- Familial hypocalciuric hypercalcemia (FHH)
Low PTH
- Malignancy
  - Humoural hypercalcemia of malignancy (HHM): mediated by PTHrP, and most common in squamous cell carcinomas
  - alpha-1 hydroxylase: lymphoma
  - Local osteolysis: multiple myeloma
  - Bony metastases: breast cancer
- Granulomatous disease (alpha-1 hydroxylase)
  - Tuberculosis
  - Sarcoidosis
- Nutritional
- Endocrine
  - Thyrotoxicosis
  - Pheochromocytoma, including in MEN-2 or via production of PTH-RP
  - Adrenal insufficiency, rarely
- Medication: thiazide diuretics, prolonged retinoic acid, calcium carbonate (causing milk-alkali syndrome)
- Prolonged immobilization, rarely
- Many other rare causes1

References

^ Yasaman Motlaghzadeh, John P Bilezikian, Deborah E Sellmeyer. Rare Causes of Hypercalcemia: 2021 Update. The Journal of Clinical Endocrinology & Metabolism. 2021;106(11):3113-3128. doi:10.1210/clinem/dgab504.

@@ Line 1: / Line 1: @@
-== Differential Diagnosis ==
+== Background ==
+=== Pathophysiology ===
-* High PTH
-** Primary hyperparathyroidism
-*** Parathyroid adenoma (most common)
-** Tertiary hyperparathyroidism
-** Familial hypocalciuric hypercalcemia (FHH)
-* Low PTH
-** Malignancy
-*** HHM (PTHrP): squamous cell carcinomas
-*** alpha-1 hydroxylase: lymphoma
-*** Local osteolysis: multiple myeloma
-*** Bony metastases: breast cancer
-** Granulomatous disease (alpha-1 hydroxylase)
-*** Tuberculosis
-*** Sarcoidosis
-** Nutritional
-*** Hypervitaminosis A
-*** Hypervitaminosis D
-*** Milk-alkali syndrome
-*** Total parenteral nutrition
-** Thyrotoxicosis
-** Prolonged immobilization
+*[[Vitamin D]] is absorbed from GI tract
-== Pathophysiology ==
+**First hydroxylation to 25-OH vitamin D in liver
+**Second hydroxylation to 1,2-OH vitamin D in kidneys by alpha-1 hydroxylase
+*PTH from parathyroid glands
+*Calcitriol is involved somewhere
+==Differential Diagnosis==
-* Vitamin D is absorbed from GI tract
-* First hydroxylation to 25-OH vitamin D in liver
+*High PTH
-* Second hydroxylation to 1,2-OH vitamin D in kidneys by alpha-1 hydroxylase
+**[[Primary hyperparathyroidism]]
-* PTH from parathyroid glands
+***[[Parathyroid adenoma]] (most common)
-* Calcitriol is involved somewhere
+**[[Tertiary hyperparathyroidism]]
+**[[Familial hypocalciuric hypercalcemia]] (FHH)
+*Low PTH
+**[[Malignancy]]
+***[[Humoural hypercalcemia of malignancy]] (HHM): mediated by PTHrP, and most common in [[Squamous cell carcinoma|squamous cell carcinomas]]
+***alpha-1 hydroxylase: [[lymphoma]]
+***Local osteolysis: [[multiple myeloma]]
+***Bony metastases: [[breast cancer]]
+**Granulomatous disease (alpha-1 hydroxylase)
+***[[Tuberculosis]]
+***[[Sarcoidosis]]
+**Nutritional
+***[[Hypervitaminosis A]]
+***[[Hypervitaminosis D]]
+***[[Milk-alkali syndrome]]
+***[[Total parenteral nutrition]]
+**Endocrine
+***[[Thyrotoxicosis]]
+***[[Pheochromocytoma]], including in [[MEN-2]] or via production of PTH-RP
+***[[Adrenal insufficiency]], rarely
+**Medication: thiazide diuretics, prolonged retinoic acid, calcium carbonate (causing [[milk-alkali syndrome]])
+**Prolonged immobilization, rarely
+**Many other rare causes[[CiteRef::motlaghzadeh2021ra]]
 [[Category:Endocrinology]]