A Case of Diffuse Pulmonary Ossification Complicated by Obstructive Pneumonia

Diffuse pulmonary ossification (DPO) is a rare and usually asymptomatic condition characterized by ectopic bone formation in the lungs. A 45-year-old man presented with a low-grade fever, cough, and fatigue. Chest computed tomography revealed a calcified lesion near the left B9 bronchus with bronchial narrowing and distal consolidation, as well as multiple small calcified nodules in the upper and lower lobes of both lungs. Bronchoscopy revealed complete obstruction of the left B9 bronchus. Transbronchial biopsy revealed cartilaginous tissue without malignancy. Despite antibiotic therapy, the symptoms persisted, and malignancy could not be excluded. Subsequently, thoracoscopic surgery was performed. Due to the strong adhesion between the lesion and the bronchus, a left basal segmentectomy was required. Histopathological examination revealed mature trabecular bone with marrow elements, consistent with pulmonary ossification. Although generally benign, pulmonary ossification can cause bronchial obstruction and refractory pneumonia and occasionally require surgical intervention.