长期慢性炎症性肠病常用的免疫抑制剂硫唑嘌呤，可能与一些白血病等恶性肿瘤的风险增加有关。一个年龄为50岁的男性患者有27年的克罗恩病病史，从2007年以来一直接受2.5毫克/千克/天（150毫克/天）剂量的硫唑嘌呤治疗，术后回肠盲袢切除术以预防术后复发。十年后，患者出现情况持续恶化和发热的3周病史。体格检查显示皮肤苍白和发热。生化评估显示全血细胞减少症。疑似硫唑嘌呤的造血毒性作用。马上停用该药。骨髓活检结合免疫表型研究确认了急性髓系白血病的诊断。需要化疗，但患者在2周后去世。硫唑嘌呤可能与治疗相关的急性髓系白血病有关。密切监测其造血毒性，并对患者进行教育以遵守此监测计划，对于检测这种危及生命的并发症至关重要。

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.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.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.