[Bone involvement in systemic mastocytosis: report of 3 cases].

Systemic mastocytosis is a rare disease, with symptoms produced by the accumulation of mastocytes on skin and other tissues as well as the release of biologically active substances. Bone is the more frequent extracutaneous involvement, its being clinically difficult to detect, even though the radiological findings detects them in at least 70% of the cases. It is necessary to notice the great variety of presentation, from localized to disseminated and osteoporotic to condensed or mixed as it is in this cases. These are reasons for diagnosis delay. The elective test in those cases with general involvement is bone biopsy; its processing the sample with blue toluidine.