Pulmonary Artery Pseudoaneurysm Caused by Pulmonary Mucormycosis

A 62-year-old woman with a background of type 2 diabetes and IgG4-related disease required medical attention because of recurring hemoptysis persisting for 3 months. The patient had previously received oral prednisolone acetate and mycophenolate acetate for effective treatment of IgG4-related disease. Hemoptysis was quantified as 10–20 ml of fresh blood daily. A chest radiograph indicated the presence of right-sided pneumonia accompanied by right pleural effusion and interlobular effusion (Figure 1A). Further assessment with contrast-enhanced chest computed tomography unveiled a pseudoaneurysm within the right lower lobe pulmonary artery (Figure 1B), which was subsequently validated by pulmonary vascular three-dimensional reconstruction (Figure 1C). After these diagnostic steps, the patient underwent bronchoscopy with biopsy for further evaluation. Microscopic examination of the biopsy tissue confirmed the diagnosis of pulmonary mucormycosis (PM) (Figure 1I). The biopsy tissue underwent next-generation sequencing, revealing an infection caused by Rhizopus oryzae. Therefore, pulmonary artery pseudoaneurysm (PAP) secondary to PM was diagnosed. The patient underwent embolization of the pseudoaneurysm and received antifungal treatment with amphotericin B cholesteryl sulfate complex. In addition, she received insulin to improve blood glucose control, and immunosuppressive drugs were discontinued. After treatment, the hemoptysis was resolved, and subsequent chest radiography at 1 and 5 months showed a significant improvement in the right lung infection and pleural effusion (Figures 1D and 1G). Contrast-enhanced chest computed tomography and pulmonary vascular three-dimensional reconstruction revealed successful occlusion of blood flow to the PAP (Figure 1F).

Figure 1.

(A) The chest radiograph shows right-sided pneumonia, right pleural effusion, and interlobular effusion. (B) Contrast-enhanced chest computed tomography (CT) reveals a pulmonary artery pseudoaneurysm in the right lower lobe pulmonary artery. (C) Pulmonary vascular three-dimensional reconstruction confirms the presence of pulmonary artery pseudoaneurysm (arrow). (D–F) Chest radiograph, contrast-enhanced chest CT, and pulmonary vascular reconstruction after treatment. (G and H) Chest radiograph and CT images 5 months after treatment. (I) Photomicrographs display aseptate thin-walled foldable fungal hyphae in the bronchoscopy biopsy (hematoxylin and eosin stain; original magnification, ×200).

PAP is a rare complication of PM and typically carries a poor prognostic outcome (1, 2). Noteworthy risk factors for mucormycosis encompass diabetes, the use of glucocorticoids or cytotoxic drugs, and solid organ or bone marrow transplant (3). Mucorales species are characterized by angioinvasion, leading to vessel rupture and substantial hemorrhage (4). The recommended approach for mucormycosis involves the administration of liposomal amphotericin B accompanied by surgical intervention. Given the substantial risk of rupture and death associated with large PAP, PAP embolization can be considered as a bridge to definitive surgery (5).