osteoma

The spongy or cancellous osteoma is really an ossified chondroma, and is met with at the ends of the long bones (Fig. 52).

The ivory or compact osteoma is composed of dense bone, and usually grows from the skull.

Subungual exostosis is an osteoma growing from the terminal phalanx of the great toe (Fig. 107).

Clinically, the osteoma forms a hard, indolent tumour attached to a bone.

Osteoma—usually the ivory variety—may originate in the wall of the orbit, or may spread from the adjacent sinuses.