Abstract: Pulmonary mucormycosis is a severe and often fatal disease that commonly affects patients with underlying conditions, such as diabetes. Early diagnosis and appropriate treatment are crucial for improving survival rates. However, clinical diagnosis remains challenging due to difficulty in obtaining etiological evidence. In this particular case, the patient presented with a cough-producing bloody sputum, and a chest CT revealed lesions in the right upper lobe of the lung. The patient was ultimately diagnosed with pulmonary mucormycosis caused by Rhizopus delemar through clinical bronchoscopy biopsy and metagenomic next-generation sequencing (mNGS) analysis of bronchoalveolar lavage fluid sample. Subsequently, antifungal therapy using the less toxic Amphotericin B cholesterol Organosulfate complex was initiated, improving the patient’s condition. In conclusion, our findings underscore the potential of mNGS to provide an accurate and rapid etiological diagnosis of pulmonary mucormycosis, offering a foundation for treatment.

Keywords: Rhizopus delemar, pulmonary mucormycosis, metagenomic next generation sequencing, bronchoscopy biopsy