目的　探讨胸膜肺母细胞瘤的早期诊断及治疗。方法　回顾性分析1例由1型胸膜肺母细胞瘤逐渐进展为3型患儿的诊治过程。结果　患儿，男，生后18 d胸片未见明显异常；1岁时胸片示左肺近肺门处囊性占位，约5 cm×4 cm×4 cm，考虑为先天性肺囊性腺瘤样畸形，家长拒绝手术；3岁2个月，胸片及胸部CT提示左肺囊性实性占位，体积较前明显增大，背侧为实性，上部位巨大含气空腔；2个月后患儿出现呼吸喘憋，复查胸部CT示肿瘤完全实变，考虑胸膜肺母细胞瘤3型。手术切除后常规化疗，随访1年尚未复发。结论　1型胸膜肺母细胞瘤与先天性肺囊性腺瘤样畸形不宜鉴别，早期诊断及治疗可改善1型胸膜肺母细胞瘤的预后。

Objective　To investigate the early diagnosis and treatment of pleuropulmonary blastoma in children. Methods  The progress of pleuropulmonary blastoma from type 1 to type 3 was retrospectively analyzed. Results  The male infant had no obvious abnormality in chest X-ray at 18 days. At one year old, X-ray film of the chest showed cystic lesions near hilum of the left lung (about 5 cm × 4 cm × 4 cm). The congenital cystic adenomatoid malformation was considered and an operation resection was suggested. However, it had been rejected by his parents. At 3 years and 2 months old, chest X-ray and CT showed left lung had a solid cystic lesion, the volume was significantly enlarged, the back side was solid and the upper part had a large gas cavity. Two months later, the patient had asthmatic suffocation. The chest CT showed the tumor was completely solid. Pleuropulmonary blastoma type 3 was considered. The patient received the conventional chemotherapy after operation excision, and was followed up for 1 year. No recurrence was observed after the treatment. Conclusions  Type 1 pleuropulmonary blastoma and congenital cystic adenomatoid malformation are hard to be differentially diagnosed. Early diagnosis and treatment of type 1 pleuropulmonary blastoma can improve the prognosis.