Approach to a patient with hypercalcemia
Introduction
- Hypercalcemia is a relatively common clinical problem. Among all causes of hypercalcemia, primary hyperparathyroidism and malignancy are the most common, accounting for greater than 90 percent of cases.[1] [2] [3]
- Hypercalcemia : Serum total calcium above 10.6 mg/dl.[4]
- This topic card will discuss how to approach a hypercalcemic patient.
History and physical examination :
- Signs and symptoms related to the Hypercalcemia itself :
- 1. Polyuria and polydipsia : Chronic Hypercalcemia cause nephrogenic diabetes insipidus.
- 2. Gastrointestinal symptoms, such as constipation, anorexia, and nausea.
- 3. Palpitations and chest pain : due to cardiac arrhythmias from severe hypercalcemia.[5]
- 4. lethargy, confusion, stupor, and coma : with severe hypercalcemia (calcium >14 mg/dL [3.5 mmol/L]) from any cause.[6]
- 5. Band keratopathy[*] : very rare finding.[7]
- Signs and symptoms related to the cause of Hypercalcemia.
- 1. For suspected Primary hyperparathyroidism: Remember “bones, stones, abdominal moans and psychic groans.”
- o Bone pain : due to Bone disease “Osteitis fibrosa cystica”.[8]
- o Renal colic : from nephrolithiasis.[8]
- o Muscle weakness and fatigue.[9] [10]
- o lethargy, depressed mood, psychosis, decreased social interaction and cognitive dysfunction : neuropsychiatric abnormalities.[11]
- o History of recurrent bone fractures especially vertebral,pelvic and distal forearm fractures.[12] [13] [14] [15] [16] [17]
- 2. History of solid or hematologic tumors especially breast , lung , multiple myeloma :For suspected malignancy .[18]
- 3. Warm moist skin,lid lag, heat intolerance, weight loss despite normal appetite and other signs and symptoms of hyperthyroidism:For suspected thyrotoxicosis.
- 4. History of immobilization.[19] [20] [21]
- 5. History of bone pain and pathological femoral fractures : For suspected paget disease of bone.
- 6. History of estrogen or estrogen antagonist intake (tamoxefin).[22] [23]
- 7. History of calcium carbonate and calcium acetate intake for chronic kidney disease and prolonged intake of milk : for suspected excessive calcium intake and milk-alkali syndrome.[24]
- 8. History of Vitamin D ingestion : for vitamin D intoxication.[25]
- 9. History of lithium or thiazide diuretics intake.
- 10. History of pheochromocytoma : due to the disease itself or associated hyperparathyroidism in MEN type 2.[26] [27] [28]
- 11. History of myalgias and brown to red urine : for suspected rhabdomyalysis and acute renal failure.[29] [30]
- 12. History of thyophilline intake : for suspected thyophilline toxicity. [31]
Diagnostic approach : See algorithm.
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- Step one: Serum total calcium level.
- Step two : Correction of serum calcium level for albumin level to exclude pseudohypercalcemia (facticious Hypercalcemia) by the following equation :
- corrected Ca = SerumCa + 0.8 * (NormalAlbumin - PatientAlbumin)[†]
- Step three : Serum parathyroid hormone level(PTH) : To distinguish PTH-dependent from PTH-independent Hypercalcemia.
- Elevated or high normal PTH indicates PTH-dependent Hypercalcemia, while decreased levels (<20 pg/ml) indicates PTH-independent causes.
- Step four (A) : In PTH-dependent cases do the following :
- 1. Urinary execration of Ca+2 : to discriminate primary hyper-PTH from Familial hypocalciuric Hypercalcemia (FHH).
- Urinary execration of Ca+2 is elevated in primary hyper-PTH and decreased in FHH.
- 2. Consider tertiary hyper-PTH from prolonged secondary hyper-PTH. [32] [33]
- 3. Consider lithium and thyophilline toxicity.
- Step four (B) : In PTH-independent cases do serum phosphate level.
- Step five (A): If serum phosphate level is low, do Parathyroid-hormone related peptide (PhRP) level : to assess for Hypercalcemia of malignancy.[34]
- Step five (B) : If serum phosphate level is high do the following :
- 1. Chest x-ray : for suspected granulomatous disease.
- 2. Vitamin D metabolites, 25-hydroxyvitamin D (calcidiol) and 1,25-dihydroxyvitamin D (calcitriol) level : for vitamin D intoxication.[35]
- 3. TSH and T4 : for suspected hyperthyroidism.[36]
- 4. serum and urinary protein electrophoresis : for suspected multiple myeloma.[36]
- 5. Serum Chloride level and arterial blood gases : a low serum chloride concentration and metabolic alkalosis are characteristic of the milk-alkali syndrome.
- 6. Bone scan : for suspected metastatic bone disease.
- 7. Vitamin A : for suspected hypervitaminosis A.[36]
- 8. Consider immobilization.
Clinical Clues :
- The degree of hypercalcemia also may be useful diagnostically.
- o Primary hyperparathyroidism is often associated with borderline or mild hypercalcemia (serum calcium concentration often below 11 mg/dL [2.75 mmol/L]).
- o Values above 13 mg/dL (3.25 mmol/L) are more common in patients with malignancy-associated Hypercalcemia.
- PhRP is usually not necessary for diagnosis since most patients have clinically apparent malignancy at the time of Hypercalcemia.
- There appears to be a higher incidence of primary hyperparathyroidism in patients with malignancy than in the general population [2][3]. Thus, despite the increased cost, it is reasonable to order an intact PTH assay as part of the routine evaluation for hypercalcemia even in a patient with known malignant disease.
- Vitamin D metabolites :
- o elevated 25-hydroxyvitamin D (25OHD) is indicative of vitamin D intoxication due to the ingestion of either vitamin D or calcidiol itself.[37] [38]
- o elevated 1,25-dihydroxyvitamin D may be induced by
- 1. direct intake of this metabolite.
- 2. extrarenal production in granulomatous diseases or lymphoma.
- 3. increased renal production that can be induced by primary hyperparathyroidism but not by PTHrp.[39]
- Other tests that can be helpful :
- o Urinary execretion of calcium.
- • Elevated or high normal in hyperparathyroidism and hypercalcemia of malignancy.
- • Decreased in The milk-alkali syndrome, Thiazide diuretics and FHH.
- o Chloride level :
- • elevated chloride level (associated with a mild fall in the serum bicarbonate concentration) is consistent with primary hyperparathyroidism.
- • Remember a low serum chloride concentration and metabolic alkalosis are characteristic of the milk-alkali syndrome.
- o Bone x-ray : evidence of osteitis fibrosa on bone films is very specific for primary hyperparathyroidism .
References
- [*] a reflection of subepithelial calcium phosphate deposits in the cornea
- [†] some authorities prefer to measure the serum ionized calcium.
- [1] Lafferty FW. Differential diagnosis of hypercalcemia. J Bone Miner Res 1991; 6 Suppl 2:S51.
- [2] Burtis WJ, Wu TL, Insogna KL, Stewart AF. Humoral hypercalcemia of malignancy. Ann Intern Med 1988; 108:454.
- [3] Ratcliffe WA, Hutchesson AC, Bundred NJ, Ratcliffe JG. Role of assays for parathyroid-hormone-related protein in investigation of hypercalcaemia. Lancet 1992; 339:164.
- [4] Blood Test Results - Normal Ranges
- [5] Rosenqvist M, Nordenström J, Andersson M, Edhag OK. Cardiac conduction in patients with hypercalcaemia due to primary hyperparathyroidism. Clin Endocrinol (Oxf) 1992; 37:29.
- [6] Shane, E, Dinaz, I. Hypercalcemia: Pathogenesis, clinical manifestations, differential diagnosis, and managment. In: Favus, MJ, ed. Primer on the metabolic bone diseases and disorders of mineral metabolism. Sixth ed. Philadelphia: Lippincott, Williams, and Wilkins. 2006; 26:176.
- [7] Wilson KS, Alexander S, Chisholm IA. Band keratopathy in hypercalcemia of myeloma. Can Med Assoc J 1982; 126:1314.
- [8] Silverberg SJ, Bilezikian JP. Evaluation and management of primary hyperparathyroidism. J Clin Endocrinol Metab 1996; 81:2036.
- [9] Lundgren E, Ljunghall S, Akerström G, et al. Case-control study on symptoms and signs of "asymptomatic" primary hyperparathyroidism. Surgery 1998; 124:980.
- [10] Mallette LE, Bilezikian JP, Heath DA, Aurbach GD. Primary hyperparathyroidism: clinical and biochemical features. Medicine (Baltimore) 1974; 53:127.
- [11] Coker LH, Rorie K, Cantley L, et al. Primary hyperparathyroidism, cognition, and health-related quality of life. Ann Surg 2005; 242:642.
- [12] De Geronimo S, Romagnoli E, Diacinti D, et al. The risk of fractures in postmenopausal women with primary hyperparathyroidism. Eur J Endocrinol 2006; 155:415.
- [13] Dauphine RT, Riggs BL, Scholz DA. Back pain and vertebral crush fractures: an unemphasized mode of presentation for primary hyperparathyroidism. Ann Intern Med 1975; 83:365.
- [14] Kenny AM, MacGillivray DC, Pilbeam CC, et al. Fracture incidence in postmenopausal women with primary hyperparathyroidism. Surgery 1995; 118:109.
- [15] Melton, LJ 3rd, Atkinson, EJ, O'Fallon, WM, Heath, H 3rd. Risk of age-related fractures in patients with primary hyperparathyroidism. Arch Intern Med 1992; 152:2269.
- [16] Khosla S, Melton LJ 3rd, Wermers RA, et al. Primary hyperparathyroidism and the risk of fracture: a population-based study. J Bone Miner Res 1999; 14:1700.
- [17] Wilson RJ, Rao S, Ellis B, et al. Mild asymptomatic primary hyperparathyroidism is not a risk factor for vertebral fractures. Ann Intern Med 1988; 109:959.
- [18] Stewart AF. Clinical practice. Hypercalcemia associated with cancer. N Engl J Med 2005; 352:373.
- [19] Stewart AF, Adler M, Byers CM, et al. Calcium homeostasis in immobilization: an example of resorptive hypercalciuria. N Engl J Med 1982; 306:1136.
- [20] Alborzi F, Leibowitz AB. Immobilization hypercalcemia in critical illness following bariatric surgery. Obes Surg 2002; 12:871.
- [21] Massagli TL, Cardenas DD. Immobilization hypercalcemia treatment with pamidronate disodium after spinal cord injury. Arch Phys Med Rehabil 1999; 80:998.
- [22] Legha SS, Powell K, Buzdar AU, Blumenschein GR. Tamoxifen-induced hypercalcemia in breast cancer. Cancer 1981; 47:2803.
- [23] Valentin-Opran A, Eilon G, Saez S, Mundy GR. Estrogens and antiestrogens stimulate release of bone resorbing activity by cultured human breast cancer cells. J Clin Invest 1985; 75:726.
- [24] Meric F, Yap P, Bia MJ. Etiology of hypercalcemia in hemodialysis patients on calcium carbonate therapy. Am J Kidney Dis 1990; 16:459.
- [25] Selby PL, Davies M, Marks JS, Mawer EB. Vitamin D intoxication causes hypercalcaemia by increased bone resorption which responds to pamidronate. Clin Endocrinol (Oxf) 1995; 43:531.
- [26] Heath DA. Primary hyperparathyroidism. Clinical presentation and factors influencing clinical management. Endocrinol Metab Clin North Am 1989; 18:631.
- [27] Stewart AF, Hoecker JL, Mallette LE, et al. Hypercalcemia in pheochromocytoma. Evidence for a novel mechanism. Ann Intern Med 1985; 102:776.
- [28] Bridgewater JA, Ratcliffe WA, Bundred NJ, Owens CW. Malignant phaeochromocytoma and hypercalcaemia. Postgrad Med J 1993; 69:77.
- [29] Llach F, Felsenfeld AJ, Haussler MR. The pathophysiology of altered calcium metabolism in rhabdomyolysis-induced acute renal failure. Interactions of parathyroid hormone, 25-hydroxycholecalciferol, and 1,25-dihydroxycholecalciferol. N Engl J Med 1981; 305:117.
- [30] Akmal M, Bishop JE, Telfer N, et al. Hypocalcemia and hypercalcemia in patients with rhabdomyolysis with and without acute renal failure. J Clin Endocrinol Metab 1986; 63:137.
- [31] McPherson ML, Prince SR, Atamer ER, et al. Theophylline-induced hypercalcemia. Ann Intern Med 1986; 105:52.
- [32] Arnold A, Brown MF, Ureña P, et al. Monoclonality of parathyroid tumors in chronic renal failure and in primary parathyroid hyperplasia. J Clin Invest 1995; 95:2047.
- [33] Drüeke TB. The pathogenesis of parathyroid gland hyperplasia in chronic renal failure. Kidney Int 1995; 48:259.
- [34] Ratcliffe WA, Hutchesson AC, Bundred NJ, Ratcliffe JG. Role of assays for parathyroid-hormone-related protein in investigation of hypercalcaemia. Lancet 1992; 339:164.
- [35] Rosol TJ, Capen CC. Mechanisms of cancer-induced hypercalcemia. Lab Invest 1992; 67:680.
- [36] Beall DP, Scofield RH. Milk-alkali syndrome associated with calcium carbonate consumption. Report of 7 patients with parathyroid hormone levels and an estimate of prevalence among patients hospitalized with hypercalcemia. Medicine (Baltimore) 1995; 74:89.
- [37] Kimball S, Vieth R. Self-prescribed high-dose vitamin D3: effects on biochemical parameters in two men. Ann Clin Biochem 2008; 45:106.
- [38] Jacobus CH, Holick MF, Shao Q, et al. Hypervitaminosis D associated with drinking milk. N Engl J Med 1992; 326:1173.
- [39] Schilling T, Pecherstorfer M, Blind E, et al. Parathyroid hormone-related protein (PTHrP) does not regulate 1,25-dihydroxyvitamin D serum levels in hypercalcemia of malignancy. J Clin Endocrinol Metab 1993; 76:801.