Sandbox : anmol
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Hyperparathyroidism Microchapters |
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Diagnosis |
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Treatment |
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Case Studies |
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Anmol Pitliya, M.B.B.S. M.D.[2]
Classification
| Classification of hyperparathyridism | |||
|---|---|---|---|
| Features | Primary hyperparathyroidism | Secondary hyperparathyroidism | Tertiary hyperparathyroidism |
| Pathology | Hyperfunction of parathyroid cells due to hyperplasia, adenoma or carcinoma. | Physiological stimulation of parathyroid in response to hypocalcaemia. | Following long term physiological stimulation leading to hyperplasia. |
| Cause | |||
| Associations | May be associated with multiple endocrine neoplasia. | Usually due to chronic renal failure or other causes of Vitamin D deficiency. | Seen in chronic renal failure. |
| Serum calcium | High | Low/Normal | High |
| Serum phosphate | Low/Normal | High | High |
| Management | Usually surgery if symptomatic. Cincacalcet can be considered in those not fit for surgery. | Treatment of underlying cause. | Usually cinacalcet or surgery in those that don't respond. |
Causes
Overview
Hyperparathyroidism is caused by an increase in concentration of parathyroid hormone in serum. There are three type of hyperparathyroidism including primary, secondary and tertiary hyperparathyroidism. The causes of all hyperparathyroidism is different.
Causes of Primary hyperparathyroidism
Causes of primary hyperparathyroidism are as follows:
Common causes
- Parathyroid adenoma
- Usually single gland affected
- Sometimes multiple gland affected
Less common causes
- Parathyroid hyperplasia
- Parathyroid carcinoma
- Radiation exposure (due to development of parathyroid adenoma or parathyroid hyperplasia)[1][2][3]
Genetic causes
- HRPT2 gene mutations:[4]
- HRPT2 gene code for parafibromin protein.
- HRPT2 gene mutations are found in a type of familial hyperparathyroidism, hyperparathyroidism-jaw tumor (HPT-JT) syndrome.
- HRTP2 gene mutations increases risk of parathyroid carcinoma.
- Cyclin D1 gene (CCND1)/PRAD1 gene:[5][6]
- PRAD1 (parathyroid adenoma 1) is a protooncogene located on chromosome 11q13.
- Cyclin D1 gene translocation and oncogene action observerd in 8% of adenomas
- Cyclin D1 gene overexpression is pbserved in 20% to 40% of parathyroid adenomas
- MEN1 gene:[5][7]
- MEN1 is a tumor supressor gene on chronosome 11q13.
- Somatic loss of single MEN1 allele is observed in 25% to 40% of sporadic parathyroid adenomas.
Causes of secondary hyperparathyroidism
Causes of secondary hyperparathyroidism are as follows:
Common causes
- Chronic renal failure (leading to parathyroid hyperplasia)[8]
- Vitamin D deficiency
Less common causes
- Severe calcium deficiency
Causes of tertiary hyperparathyroidism
Causes of tertiary hyperparathyroidism are as follows:
Common causes
- Chronic renal failure
References
- ↑ Boehm BO, Rosinger S, Belyi D, Dietrich JW (2011). "The parathyroid as a target for radiation damage". N Engl J Med. 365 (7): 676–8. doi:10.1056/NEJMc1104982. PMID 21848480.
- ↑ McMullen T, Bodie G, Gill A, Ihre-Lundgren C, Shun A, Bergin M; et al. (2009). "Hyperparathyroidism after irradiation for childhood malignancy". Int J Radiat Oncol Biol Phys. 73 (4): 1164–8. doi:10.1016/j.ijrobp.2008.06.1487. PMID 18774659.
- ↑ Tisell LE, Hansson G, Lindberg S, Ragnhult I (1977). "Hyperparathyroidism in persons treated with X-rays for tuberculous cervical adenitis". Cancer. 40 (2): 846–54. PMID 890665.
- ↑ Shattuck TM, Välimäki S, Obara T, Gaz RD, Clark OH, Shoback D; et al. (2003). "Somatic and germ-line mutations of the HRPT2 gene in sporadic parathyroid carcinoma". N Engl J Med. 349 (18): 1722–9. doi:10.1056/NEJMoa031237. PMID 14585940.
- ↑ 5.0 5.1 Westin G, Björklund P, Akerström G (2009). "Molecular genetics of parathyroid disease". World J Surg. 33 (11): 2224–33. doi:10.1007/s00268-009-0022-6. PMID 19373510.
- ↑ Hsi ED, Zukerberg LR, Yang WI, Arnold A (1996). "Cyclin D1/PRAD1 expression in parathyroid adenomas: an immunohistochemical study". J Clin Endocrinol Metab. 81 (5): 1736–9. doi:10.1210/jcem.81.5.8626826. PMID 8626826.
- ↑ Agarwal SK, Kester MB, Debelenko LV, Heppner C, Emmert-Buck MR, Skarulis MC; et al. (1997). "Germline mutations of the MEN1 gene in familial multiple endocrine neoplasia type 1 and related states". Hum Mol Genet. 6 (7): 1169–75. PMID 9215689.
- ↑ Rodriguez M, Nemeth E, Martin D (2005). "The calcium-sensing receptor: a key factor in the pathogenesis of secondary hyperparathyroidism". Am J Physiol Renal Physiol. 288 (2): F253–64. doi:10.1152/ajprenal.00302.2004. PMID 15507543.