中文摘要：

目的探讨慢性中性粒细胞白血病（CNL）合并多发性骨髓瘤（MM）的诊断和治疗。方法总结2例CNL合并MM患者的临床特征、分子生物学特点，对其诊断、治疗进行回顾性分析。结果2例患者均符合CNL合并MM的诊断。例1随着MM达完全缓解，中性粒细胞计数恢复正常；MM复发后，中性粒细胞计数再次升高。例1行CSF3R、SETBP1基因突变检查显示，CSF3R外显子17突变阳性（P733T），外显子14突变阴性；SETBP1基因突变阴性。应用针对MM的方案治疗后，随着MM病情的控制，CNL亦可缓解。结论CNL合并MM临床罕见。CSF3R基因突变对于CNL的诊断具有重要意义。CNL合并MM伴CSF3R P733T突变为国际首次报道。针对MM的方案可有效治疗CNL合并MM。

英文摘要：

Objective To explored the diagnosis and treatment of chronic neutrophilic leukemia （CNL） complicated with multiple myeloma （MM）. Methods The clinical features and molecular biological characteristics of 2 patients with CNL complicated with MM were summarized, and the diagnosis and treatment of the patients were retrospectively reviewed. Results The diagnosis of CNL complicated with MM was established in 2 cases. Case 1 had CSF3R mutation（P733T）, but CSF3R-exon 14 mutation and SETBP1 mutation were all negative. The neutrophil count returned to normal when MM was successfully treated in case 1. When the patient relapsed, neutrophil count increased again. Conclusion Coexistence of CNL and MM is rare. CSF3R is a very important molecular marker for CNL. To the best of our knowledge, it＇s the first time to report the coexistence of CNL and MM carried CSF3R mutation （P733T）. Chemotherapy regimens for MM may be effective in the treatment of CNL complicated with MM.