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 <i>fibroblast growth factor 23</i>, <i>α-Klotho</i> or <i>UDP-N-acetyl-alpha-D-galactosamine: polypeptide N-acetylgalactosaminyl transferase-3</i> 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.