Diagnostic Challenges in mNGS for Pulmonary Mucormycosis Presenting with Imaging Features Resembling Those of Lung Cancer.

BACKGROUND

Pulmonary mucormycosis is a rare fungal infection with an increasing incidence in clinical reports. Its non-specific presentation often mimics lung cancer, posing significant diagnostic challenges. This report aims to improve clinician recognition of this condition.

CASE PRESENTATION: A 67-year-old woman with diabetes presented with cough and sputum production. Imaging revealed a right hilar mass with bronchial obstruction, mediastinal lymphadenopathy, and cystic cavities (Figure 1A). While initial suspicion favored lung cancer, metagenomic next-generation sequencing (mNGS) of bronchoalveolar lavage fluid (BALF) detected Rhizopus oryzae (26,879 sequences), prompting revision of the diagnosis. Antifungal therapy with amphotericin B and posaconazole resulted in clinical improvement. Follow-up imaging at 67 days showed resolution of mucormycosis (Figure 1B).

CONCLUSION

This case highlights the diagnostic challenge of pulmonary mucormycosis masquerading as malignancy. mNGS serves as a valuable tool for early pathogen identification, though its role in therapeutic monitoring requires further investigation.