Acute myeloid leukemia after 10 years of azathioprine treatment for Crohn's disease.

BACKGROUND: Azathioprine, which is an immunosuppressive agent commonly used for chronic inflammatory bowel disease, may be associated with an increased risk of certain cancers such as hematologic malignancies.

CASE REPORT: A 50-year-old man with a 27-year history of Crohn's disease had been under azathioprine treatment at a dose of 2.5 mg/kg/day (150 mg/day) since 2007, after ileocecal resection to avoid postoperative recurrences. Ten years later, the patient presented with a 3-week history of worsening general condition and fever. The physical examination revealed skin paleness and fever. The biological assessment showed pancytopenia. Hematological toxicity of azathioprine was suspected. The drug was immediately stopped. A bone marrow biopsy with immunophenotyping studies confirmed the diagnosis of acute myeloid leukemia. Chemotherapy was indicated but the patient passed away 2 weeks later.

CONCLUSION: Azathioprine may be implicated in therapy-related acute myeloid leukemia. Close monitoring of its hematological toxicity, as well as patient education to adhere to this monitoring program, are crucial to detect this life-threatening complication.