Abstract Rationale Massive hemoptysis is a leading cause of mortality in pulmonary mucormycosis, often due to pulmonary arterial invasion and rupture. However, conventional radiologic predictors such as pulmonary artery aneurysms or pseudoaneurysms are typically late findings. We aimed to identify an earlier, more sensitive imaging marker of hemorrhagic risk and to evaluate the feasibility of prophylactic pulmonary artery embolization (PPAE) in high-risk patients. Methods We retrospectively reviewed all hospitalized patients diagnosed with pulmonary mucormycosis at West China Hospital from January 2019 to December 2024. Patients were classified into massive hemoptysis (≥300 mL/24 h or bleeding causing respiratory failure, hemodynamic instability, or death) and non-massive hemoptysis groups. Two experienced thoracic radiologists independently assessed CT scans for radiologic features including cavity, necrosis, reversed halo sign, aneurysm/pseudoaneurysm, and the newly defined pulmonary artery floating sign (PAFS)—a pulmonary artery branch traversing a necrotic or cavitary lesion without visible contact with the cavity wall. Firth logistic regression identified independent predictors of massive hemoptysis. In selected high-risk patients, the safety and short-term outcomes of PPAE were evaluated. Results Fifty-seven patients were included (mean age 52.3 ± 14.9 years, 78.9% male). Massive hemoptysis occurred in 22 (38.6%) patients with 72.7% mortality. Cavitation (68.2% vs 34.3%, p=0.026) and necrosis (100% vs 74.3%, p=0.009) were more common in the massive hemoptysis group. The PAFS was detected in 18/22 (81.8%) patients with massive hemoptysis compared with 11/35 (31.4%) without (p0.001) and was the only independent predictor of massive hemoptysis (OR 26.66, 95% CI 2.22-3849.83, p=0.006). Among five patients undergoing PPAE (three with PAFS and two with aneurysm), the procedure was technically successful in all, with no procedure-related complications. Four of five (80%) survived without recurrent bleeding during 30-day follow-up. Conclusion The pulmonary artery floating sign is a novel and independent imaging predictor of massive hemoptysis in pulmonary mucormycosis, likely reflecting early arterial wall destabilization preceding pseudoaneurysm formation. Early detection of this feature may enable risk stratification and justify prophylactic pulmonary artery embolization to prevent fatal hemorrhage. Incorporating this sign into radiologic assessment could improve early intervention and outcomes in invasive fungal pulmonary disease. This abstract is funded by: Supported by: Science and Technology Department of Sichuan Province-International Science and Technology Innovation Cooperation Project, 2024YFHZ0273
Yu et al. (Fri,) studied this question.