[Osteoid osteoma. A scanning electron microscopic study].

The mineralization process of the osteoid osteoma, after removal of the organic matrix from the specimens by treatment with 6% sodium hypochlorite, has been studied by SEM. The process was characterized by calcified nodules or calcospherites, variable in size from 0,1 to 2 microns, embedded among randomly oriented collagen bundles, which delimited trabeculae of sponge primary bone. Numerous osteocytic lacunae, in various degrees of development, in the mineralizing front were present. The ultrastructural feature of the mineralization in osteoid osteoma reflected a pattern of nodular and collagenous calcification, essentially similar to primary calcification, characteristic of rapidly developing woven bone.