Juvenile nodular aponeurotic fibroma in the area of the knee joint.

A case of calcifying aponeurotic fibroma of the knee occurred in a 14-year-old boy. Review of the literature reveals that calcifying aponeurotic fibroma is an uncommon benign tumor with a tendency for local recurrence. It is manifested by a progressively growing mass involving fat, fascia, and aponeurosis. Chondroid tissue and calcification within the areas of proliferated spindle cells are the characteristic features of this lesion and differentiate it from the other forms of fibromatosis.