School ager with a lump on the forearm

Radiograph and US of pilomatricoma
AP radiograph of the forearm (left) shows a round faintly calcified lesion lateral to the diaphysis of the radius. Transverse (above right) and sagittal (below right) US images of the lesion show it to be in the subcutaneous tissues and to have a heterogenous speckled appearance.

The diagnosis was pilomatricoma.