Calcifying Aponeurotic Fibroma of the Elbow: A Case Report

Abstract

Calcifying aponeurotic fibroma is a rare soft tissue tumor that mostly occurs in the distal extremities of children and adolescents. We report here on a case of calcifying aponeurotic fibroma of the right elbow in an 8-year-old boy, and the tumor was diagnosed by surgical excision. The patient complained of painless swelling and mild limitation of the range of motion of the elbow joint. Radiologically, the mass was ill-defined and showed stippled calcification with shallow bony erosion. Microscopically, the tumor was composed of spindle cells with nodular deposits of hyalination and calcification, and these deposits were surrounded by palisading polygonal plump cells. Immunohistochemically, the tumor showed a diffuse positive expression for CD99 and negativity for smooth muscle actin, S-100 protein and CD34. The patient has been well with no signs of recurrence during the 42 months after surgery.