当前位置: 首页 > 期刊 > 《美国医学杂志》 > 2005年第10期 > 正文
编号:11357386
Tumoral calcinosis with hyperphosphatemia
http://www.100md.com 《美国医学杂志》
     Department of Pediatrics, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Pondicherry, India

    Abstract

    Tumoral calcinosis is a rare disorder of mineral metabolism among adolescents and young adults characterized by deposition of calcific masses around large joints. It is less commonly reported in pediatric population and commonly mistaken for bone tumors. Typical lab parameters include hyperphosphatemia with normal levels of serum calcium, parathyroid hormone (PTH) and alkaline phosphatase. A ten-year-old boy with typical features of tumoral calcinosis is presented.

    Keywords: Tumoral calcinosis; Mineral metabolism; Calcific masses

    Case report

    A ten-year-old boy, developmentally normal, second born to non consanguineous parents, was brought for a swelling in the right gluteal region for 6 months. It was insidious in onset, gradually increasing in size, associated with mild pain and minimal restriction of movement of the right hip. A private practitioner had attempted an incision and drainage of the swelling, considering a gluteal abscess, but was unsuccessful. On examination, he had a hard mass in the right gluteal region measuring 5x 6 cm not fixed to the overlying skin or the underlying bone. There was a similar mass in the left gluteal region. An X-Ray of the pelvis with both hip showed well defined floccular calcified lesions in the periarticular area of both hip joints Figure1. A computerized tomography of the same area confirmed that the calcified masses were not arising from the bone Figure2. The serum analysis conducted of the patient revealed the following: calcium 9.4 mg/dl, phosphorus 8.6 mg/dl, urea 19 mg/dl, creatinine 0.1mg/dl and alkaline phosphatase 229 U/L. The patient's serum, PTH and vitamin D levels were normal and the 24 hour urinary excretion of calcium and phosphate were within normal range. An ultrasonography of his abdomen showed normal kidneys and there was no evidence of calcification around other joints radiologically. He was advised dietary restriction of phosphates, oral phosphate binders and surgical excision of the calcified lesions. However, the boy was lost for follow-up.

    Discussion

    Tumoral calcinosis is a rare disorder of mineral metabolism characterized by deposition of cystic and solid calcific masses in and around large joints like hip, shoulder and elbow. Since its first description in 1899, only few cases have been reported among pediatric population. It is often familial and occurs in adolescents and young adults with a male sex predilection. At times the lesion appears to be multiple, bilateral and symmetrical. Typical lab parameters include hyperphosphatemia with normal levels of serum calcium, PTH and alkaline phosphatase.[1] In the child under study child, the young age of onset is interesting. His lab parameters were also supportive for the diagnosis. However, hyperphosphatemia could not be proved in the other family members. In this boy with hyperphosphatemia, the intramuscular injections which he would have received earlier might have predisposed for the involvement around the hip joints. The incision and drainage attempted for the same was also unnecessary and probably worsened the condition. Tumoral calcinosis may be caused by a common intrinsic proximal tubular abnormality, leading to increased phosphate reabsorption via a pathway independent of PTH. It is associated with an inherited defect in the feedback mechanism regulating 1, 25-dihydroxyvitamin D synthesis. This is shown by normal levels of 1, 25-dihydroxyvitamin D in the presence of hyperphosphatemia and normal PTH levels and explains the normal calcium levels. [2],[3],[4],[5] Deprivation of dietary phosphorus and treatment with a mixture of magnesium and aluminium hydroxide has been found to be useful.[1] However, treatment of choice is surgical excision. Tumoral calcinosis should always be considered in the differential diagnosis of bone tumor, osteomyelitis, or vaso-occlusive crisis or bone infarction in sickle cell disease by measuring the serum phosphate level. Proper diagnosis will prevent unnecessary surgical procedures or antibiotic therapy. The family can also expect a reassuring long-term prognosis despite the possibility of recurrences.[6]

    References

    1. Lufkin EG, Wilson DM, Smith LH, Bill NJ, Deluca HF, Dousa TP, Knox FG. Phosphorus excretion in Tumoral calcinosis: Response to parathyroid hormone and Acetazolamide. J Clin Endocrinol Metab 1980; 50: 648-653.

    2. Wilson MP, Lindsley CB, Warady BA, Hyperphosphatemia associated with cortical hyperostosis and tumoral calcinosis. J Pediatr 1989; 114 : 1010-1013 .

    3. Viegas SF, Evans EB, Calhoun J. Tumor calcinosis: a case report and review of the literature. J Hand Surg 1985; 10A:744-748

    4. Mitnick PD, Goldfarb S, Slatopolosky E. Calcium and phosphate metabolism in tumoral calcinosis. Ann Intern Med 1980; 92 : 482-487.

    5. Zerwekh JE, Sanders LA, Townsend J. Tumoral calcinosis: evidence of concurrent defects in renal tubular phosphorus transport in 1-alpha, 25-hydroxycholecalciferol synthesis. Calcif Tissue Int 1980; 32 : 1-6.

    6. Narchi H. Hyperostosis With Hyperphosphatemia: Evidence of Familial occurrence and Association with Tumoral Calcinosis. J Pediatr 1997; 99 : 745-748.(Mahadevan S, Adhisivam B,)