Abstract: 　Objective　To raise awareness of pulmonary mucormycosis in children with leukemia after chemotherapy. Methods　The clinical data of a child with acute B-lymphocytic leukemia (B-ALL) complicated with pulmonary mucormycosis after induction chemotherapy were retrospectively analyzed, and the related literatures were reviewed. Results　A 2-year-old girl was diagnosed with B-ALL. She developed pulmonary infection and pyopneumothorax in the period of bone marrow suppression after induction of chemotherapy. The clinical manifestations were chest pain and hemoptysis. Pulmonary CT showed right lower lung consolidation. Multiple cultures of sputum and pleural fluid were negative. Rhizopus oryzae was detected in the pleural effusion by high-throughput sequencing of the pathogens on the 22nd day after pneumothorax, and the pathogenic diagnosis was confirmed by fibrobronchoscopic biopsy. Liposomal amphotericin B (LAmB) intravenous infusion and amphotericin B (AmB) aerosol inhalation were given. On the 55th day of pneumothorax, the thoracic drainage tube was removed and the posaconazole was orally administered sequentially. After the treatment for more than 2 months, the lung CT scan showed that the right lower lung consolidation lesions were reduced. Fiberoptic bronchoscopy revealed granulation hyperplasia in the right inferior lobar bronchi. A mirror-assisted argon gas knife cleaning was performed. Posaconazole was orally administered sequentially and the chemotherapy for leukemia was continued. After 10 months, the lung lesions were obviously absorbed. Conclusions　Pulmonary mucormycosis has vascular invasiveness and is highly malignant. High throughput sequencing of infectious pathogens is helpful for early diagnosis. The combination of amphotericin B liposomes and surgery can improve prognosis.

Key words: 　leukemia; pulmonary mucormycosis;　second generation sequencing;　amphotericin B liposome; posaconazole