Familial tumoral calcinosis: a rare autosomal recessive disease

Familial tumoral calcinosis (FTC) is a rare autosomal recessive disorder where renal tubular phosphate excretion is decreased in the absence of renal failure. The underlying defect is due to inactivating mutations in the fibroblast growth factor 23, α-Klotho or UDP-N-acetyl-alpha-D-galactosamine: polypeptide N-acetylgalactosaminyl transferase-3 genes, resulting in hyperphosphatemia. Patients typically present with calcified soft tissue masses resulting from calcium phosphate deposits. Medical management with phosphate binders, a carbonic anhydrase inhibitor, in addition to limiting phosphorus intake, is the mainstay of treatment. This case serves to highlight the pathophysiology of a rare diagnosis of FTC and the efficacy of the limited therapeutic options available.