Successful treatment of hyperphosphatemic tumoral calcinosis with long-term acetazolamide

Bone. 1995 Apr;16(4 Suppl):247S-250S. doi: 10.1016/8756-3282(95)00019-a.


We describe a patient with tumoral calcinosis, in which acetazolamide (ACZ) was, for the first time, tested for its therapeutic efficacy. The 19-year-old Japanese man had been suffering from multiple recurrent calcific masses with tenderness around the finger, knee, and toe joints since 10 months of age. Radiographs revealed several calcific subcutaneous masses around the finger joints, and calcific myelitis around the right knee joint and in the calvarium. The patient had hyperphosphatemia with elevated maximal threshold of renal phosphate excretion in the presence of normal kidney function and normocalcemia, suggesting a reduced ability to excrete phosphorus in the urine. A delay of disappearance of orally administered phosphate from the blood stream was found. A serum parathyroid hormone (PTH) level was normal, and responses to PTH and ACZ were also normal regarding the induction of phosphaturia. Since the masses tended to recur easily despite repeated surgical resections, we started medical treatment with phosphorus deprivation by oral aluminum hydroxide. However, the drug alone had no effect on hyperphosphatemia or calcific lesions, and ACZ was added in expectation of making the patient's phosphorus balance negative by its phosphaturic effect. Fourteen years of administration of the two drugs apparently improved the patient's symptoms, the biochemical findings, and the calcific lesions on radiographs. Thus, ACZ appeared to be useful for tumoral calcinosis resistant to phosphorus deprivation by aluminum hydroxide alone.

Publication types

  • Case Reports

MeSH terms

  • Acetazolamide / administration & dosage
  • Acetazolamide / therapeutic use*
  • Administration, Oral
  • Adult
  • Aluminum Hydroxide / administration & dosage
  • Aluminum Hydroxide / pharmacology
  • Aluminum Hydroxide / therapeutic use
  • Calcinosis / drug therapy*
  • Calcinosis / etiology
  • Drug Therapy, Combination
  • Fingers / diagnostic imaging
  • Fingers / pathology
  • Humans
  • Japan
  • Joint Diseases / drug therapy*
  • Joint Diseases / etiology
  • Knee Joint / diagnostic imaging
  • Knee Joint / drug effects
  • Knee Joint / pathology
  • Male
  • Parathyroid Hormone / blood
  • Phosphates / blood*
  • Phosphates / urine
  • Radiography
  • Toes / diagnostic imaging
  • Toes / pathology


  • Parathyroid Hormone
  • Phosphates
  • Aluminum Hydroxide
  • Acetazolamide