Cutaneous calculus - its pathogenesis.

The cutaneous calculus of 11 patients were examined. Histologically they were classified into three types: the first type, seen in an early lesion, consisted of a basophilic mass; the second type consisted of a mass and various-sized granules; and the third type consisted entirely of granules. Histochemically, the mass contained acid mucopolysaccharides. In the granules neutral mucopolysaccharides were found. There were numerous, vacuolated mast cells and various-sized, calcified amorphous areas evident with electron microscopic examination of an early lesion.