Pulmonary mucormycosis complicated by necrotizing pneumonia secondary to an obstructive endobronchial tumor-like lesion: a case report and review of literature

Background Mucormycosis is a rare but life-threatening invasive fungal infection, most commonly affecting immunocompromised individuals, especially those with poorly controlled diabetes mellitus. Pulmonary mucormycosis (PM) represents the second most frequent clinical form after rhino-orbital-cerebral disease and carries a high mortality rate. Diagnosis is often delayed because its clinical and radiological manifestations overlap with other pulmonary infections and malignancies. Necrotizing pneumonia secondary to endobronchial mucormycosis is exceptionally rare, representing a distinct and severe form of pulmonary involvement, with only sporadic cases reported in the literature. Case presentation A 71-year-old female farmer with previously undiagnosed and poorly controlled diabetes presented with progressive dyspnea, fever, productive cough, and weight loss. Initial chest computed tomography demonstrated necrotizing pneumonia in the right lower lobe. Broad-spectrum antibiotics failed to improve her condition, and cultures for bacteria, fungi, and Mycobacterium tuberculosis were negative. Flexible bronchoscopy revealed an endobronchial mass with whitish pseudomembranes nearly occluding the right lower lobe bronchus. Biopsy was complicated by profuse bleeding, which was controlled with local adrenaline. Histopathological examination confirmed endobronchial mucormycosis with extensive tissue necrosis, and intravenous amphotericin B was promptly initiated. The patient was later transitioned to oral posaconazole, resulting in gradual clinical and radiological improvement. Follow-up imaging at three and six months demonstrated complete resolution. Conclusion This case illustrates a rare presentation of necrotizing pneumonia secondary to endobronchial mucormycosis in a diabetic patient. Histopathological confirmation remains essential for diagnosis, particularly in patients presenting with necrotizing pneumonia and mass-like airway lesions unresponsive to antibiotics. Early recognition, timely antifungal therapy, and prolonged follow-up with serial imaging are critical to achieving full recovery and preventing recurrence.