Abstract: Objective  To improve the understanding of the clinical characteristics of pulmonary mucormycosis and analyze the risk factors of death in patients with pulmonary mucormycosis. Methods  Twenty-five cases of pulmonary mucormycosis hospitalized in Beijing Chaoyang Hospital, Capital Medical University from January 2017 to June 2023 were retrospectively collected including the risk factors, clinical manifestations, laboratory test, radiological features, treatment prognosis, etc. Among them, the risk factors, clinical manifestations, radiological features and prognosis data were analyzed by Fisher precise test. Independent sample t test or Mann-Whitney U test were used for laboratory test data. Univariate regression analysis was performed for statistically significant parameters to find risk factors for the death of pulmonary mucormycosis. Results  Among the 25 patients, male accounted for 15/25, aged (52.64±13.74) （32-76) years, and the length of hospitalization was 15 (10.5, 21.5) days. The most common risk factors for pulmonary mucormycosis were diabetes (20/25), glucocorticoid exposure (13/25),  insensitive antifungal drug use (10/25), and solid organ transplantation (5/25). The most common clinical symptoms were fever (21/25) and cough (21/25), followed by dyspnea (10/25), hemoptysis or bloody sputum (9/25). Among them, 8 patients died. Compared with the surviving patients, the patients in the death group had a shorter hospital stay (P=0.003) and a higher proportion of solid organ transplantation history (P=0.023). There was no difference in other general conditions and risk factors between the two groups. Platelet levels in the death group were lower than those in the survival group ［174 (78,227)×10⁹/L vs 310 (229,347)×10⁹/L］, and the difference was statistically significant (P=0.030). Among the 25 patients, the most common mucor fungi were Rhizopus  （including Rhizopus arrhizus, Rhizopus microsporus, etc.） and Rhizomucors (mainly Rhizomucor pusillus). Multiple pulmonary nodules were the most common imaging change in the survival group, and the difference between the two groups was statistically significant (P=0.042). Mucor pulmonary treatment included sensitive antifungal agents and surgical or interventional therapy, and there was no significant difference in treatment between surviving and dying patients. Solid organ transplantation increased the risk of death in patients with pulmonary mucormycosis (OR=16.000, 95% CI: 1.381-185.405, P=0.027). Conclusions Diabetes mellitus, glucocorticoid exposure, the use of immunosuppressive agents and solid organ transplantation are common risk factors for pulmonary mucormycosis. Most of its clinical manifestations and laboratory tests are nonspecific, and the common imaging features include multi-lobed lesions, pleural effusion, tracheal stenosis or occlusion, cuneate compactness, and multiple pulmonary nodules. Among the above clinical features, patients with lower platelet levels and solid organ transplant recipients had a higher mortality rate, and solid organ transplantation increased the risk of death in patients with pulmonary mucormycosis.

Key words: pulmonary mucormycosis, solid organ transplantation, prognosis