以双下肢水肿起病的老年T/髓系混合表型急性白血病并发血栓–感染双重危象

T/Myeloid Mixed‑Phenotype Acute Leukemia in an Elderly Patient Presenting with Bilateral Lower Extremity Edema and Concurrent Thrombosis‑Infection Crisis

摘要: 混合表型急性白血病(mixed-phenotype acute leukemia, MPAL)是一种罕见的急性白血病，占全部急性白血病的2%~5%，以髓系和淋系抗原共表达为特征，总体预后较差，老年患者尤为突出。MPAL的临床表现与单一表型急性白血病相似，缺乏特异性；以双下肢水肿为首发表现者极为罕见，极易被误诊为心源性、肾源性或营养性水肿，造成诊断延迟。本文报道1例69岁确诊为T/髓系MPAL的老年男性患者，初始治疗予VA方案(阿扎胞苷联合维奈克拉)，仅用药1天患者即出现胸闷、憋气等不适，家属要求终止化疗并拒绝后续原发病治疗。后患者反复发热，病原学检查先后检出多重耐药菌。白血病所致高凝状态、左上臂输液港置入及严重的全身性感染与炎症反应相互叠加，继发上肢深静脉血栓形成。经过抗感染及利伐沙班抗凝等综合支持治疗，患者症状部分缓解，但原发病始终未获控制。住院期间，患者家属多次拒绝重启化疗、输注血制品及手术取栓等积极干预措施，最终自动出院。本病例提示：老年T/髓系MPAL对化疗耐受性差，早期中断治疗后可并发致命的“血栓–感染双重危象”，临床预后极差。对于此类高龄、不宜或拒绝强烈化疗的患者，在积极抗感染和审慎抗凝支持的同时，应积极与家属沟通，尽早制定个体化姑息减症策略，充分权衡血栓与出血风险，以最大程度改善终末期生存质量。

Abstract: Mixed-phenotype acute leukaemia (MPAL) is a rare form of acute leukaemia, accounting for 2% to 5% of all acute leukaemias. It is characterised by the co-expression of myeloid and lymphoid antigens and has a generally poor prognosis, which is particularly pronounced in elderly patients. The clinical presentation of MPAL is similar to that of single-phenotype acute leukaemia and lacks specificity; it is extremely rare for the initial presentation to be oedema of both lower limbs, which is very easily misdiagnosed as cardiac, renal or nutritional oedema, leading to diagnostic delay. This report describes a 69-year-old male patient diagnosed with T/myeloid MPAL. Initial treatment with the VA regimen (azacitidine combined with venetoclax) was initiated; however, after only one day of treatment, the patient developed symptoms such as chest tightness and shortness of breath. The family requested that chemotherapy be discontinued and refused further treatment for the underlying disease. Subsequently, the patient experienced recurrent fever, and microbiological tests successively identified multidrug-resistant bacteria. The hypercoagulable state caused by leukaemia, combined with the placement of an intravenous port in the left upper arm and severe systemic infection and inflammatory response, led to secondary deep vein thrombosis in the upper limb. Following comprehensive supportive treatment, including antimicrobial therapy and rivaroxaban anticoagulation, the patient’s symptoms partially resolved; however, the underlying disease remained uncontrolled. During hospitalisation, the patient’s family repeatedly refused active interventions, such as resuming chemotherapy, blood product transfusions and surgical thrombectomy, and the patient ultimately discharged himself. This case highlights that elderly patients with T-cell/myeloid MPAL have poor tolerance to chemotherapy; early discontinuation of treatment may lead to a life-threatening “thrombotic-infectious dual crisis”, with an extremely poor clinical prognosis. For such elderly patients who are unsuitable for or refuse intensive chemotherapy, whilst providing active anti-infective and prudent anticoagulation support, clinicians should actively communicate with the family to formulate individualised palliative and symptom-relief strategies at the earliest opportunity, carefully balancing the risks of thrombosis and haemorrhage to maximise quality of life in the terminal phase.