De novo acute myeloid leukemia in patients with Crohn's disease.

Crohn's disease (CD) has been occasionally reported to be associated with myelodysplastic syndromes (MDS) or acute myeloid leukaemia (AML). From October 1991 to June 1993, four AML patients with a previous history of CD but no history of MDS were referred to our institution. Three presented AML with a monoblastic proliferation (one AML4 and two AML5). Cytogenetic analysis revealed a normal karyotype in two patients, an inv(16) in another and a del(11)(q24-25) in the fourth. Interestingly, the three patients with AML4/AML5 had not received high doses of immunosuppressive agents, prior CD therapy ranging from 1 to 4 months sulfasalazine with additional azathioprine in one case.