Childhood calcinosis cutis.

Calcinosis cutis, an uncommon disorder characterized by hydroxyapatite crystals of calcium phosphate deposited in the skin, has been described infrequently in childhood. Classically, it is divided into dystrophic, metastatic, and idiopathic types. We report an 8-year-old girl with hyperphosphatemia secondary to a tumor lysis syndrome, who developed a localized soft tissue calcification over a previous lesion of ecthyma gangrenosum. Intravenous infusion of calcium gluconate was probably the precipitating factor. Our case illustrates that several etiopathogenic mechanisms may be simultaneously involved in calcinosis cutis.