Tumoral calcinosis: scintigraphic studies of an affected family.

Tumoral calcinosis is a rare, familial ectopic calcification syndrome associated with hyperphosphataemia. A family in which seven of 13 siblings had demonstrable, clinical, radiological and pathological findings of tumoral calcinosis was evaluated. The purposes were to compare the efficacy of bone scintiscans with serum phosphorus determination in detecting subclinical disease early in asymptomatic siblings and to assess therapeutic results in affected family members following initiation of phosphate depletion therapy. History, physical examination, serum calcium, serum phosphorus and bone scintiscans were performed in 12 of 13 siblings. All the affected siblings had markedly elevated serum phosphorus levels and abnormal bone scintiscans while the unaffected siblings had normal serum phosphorus levels and normal bone scintiscans. All the siblings, affected and unaffected, were normocalcaemic. After initiation of phosphate depletion therapy, gross changes in the appearance of lesions were detected on bone scintiscans. Serum phosphorus levels likewise showed a modest decline, although still remaining in the hyperphosphataemic range. In conclusion, bone scintiscans and serum phosphorus determinations are equally sensitive in detecting subclinical disease. However, the scintiscans are helpful in assessing not only the extent of the disease, but also whole-body and regional changes following any therapeutic interventions.