Systemic mastocytosis associated with chronic myelomonocytic leukemia and xanthogranuloma

A patient with a history of non-diagnostic bone marrow biopsies presented with a red to brown maculopapular rash on the back. Biopsies confirmed multiple xanthogranulomas as well as a mastocytosis. A consequently performed bone marrow biopsy verified a systemic mastocytosis and a chronic myelomonocytic leukemia (CMML) type I. Here, we describe for the first time in the literature a patient with three diseases occurring synchronously: CMML, xanthogranulomas and systemic mastocytosis. Two of them at a time are known to be associated and may be indicative of a common progenitor cell.