A unique association of unilateral idiopathic calcinosis cutis with ipsilateral porokeratotic eccrine ostial and dermal duct nevus.

An 11-year-old boy presented with complaints of multiple skin-colored hard lumps on the right side of his body and progressive deformity of the right leg of 7-years duration. His parents had also noticed multiple asymptomatic pits over his right arm, palms, and soles since childhood. Examination revealed skin-colored nontender nodules on the right half of his body and shortening of his right leg. The multiple hyperpigmented pits over the right arm, palm, and sole raised diagnostic difficulties, but histopathologic, radiologic, and biochemical investigations confirmed the features of idiopathic calcinosis cutis and porokeratotic eccrine ostial and dermal duct nevus. Unilateral idiopathic calcinosis cutis has not been previously reported in the literature, and the association with ipsilateral porokeratotic eccrine ostial and dermal duct nevus makes this case unique. Diagnostic difficulties and limited options for treatment make this case interesting academically.