Calcifying (juvenile) aponeurotic fibroma of the scalp

Calcifying aponeurotic fibroma is a benign tumor with a predilection for distal parts of the extremities; it is very rare in the head and neck region. It commonly affects young patients-hence the term juvenile in the name. It is fibroblastic in origin and considered a cartilage analogue of fibromatosis, but its exact etiology remains unknown. Clinically, this tumor needs to be differentiated from fibromatosis, nodular fasciitis, chondroma, schwannoma, and rheumatoid nodule. A 24-year-old woman presented with swelling in the forehead for the previous 6 months. Wide surgical excision of the lesion was performed, and histopathologic examination revealed a calcifying aponeurotic fibroma. We reviewed the literature on this rare clinical entity and present our hypothesis on its etiology.