Mastocytosis and diffuse large B-cell lymphoma, an unlikely combination.

Systemic mastocytosis may be accompanied by a second haematological malignancy, usually of myeloid origin. However, a number of case reports describe systemic mastocytosis coexisting with a second haematological malignancy of lymphoid origin. Here, we report a case of a 74-year-old man with systemic mastocytosis who developed a diffuse large B-cell lymphoma. A short overview of the literature concerning mastocytosis accompanied by a second haematological malignancy is presented.