A 78-year-old man non-smoker presented with a 1-week history of cough and blood-tinged sputum. There was no history of tuberculosis. A physical examination was unremarkable. The arterial blood pressure was 100/70 mm Hg, pulse 86/min, respiratory rate 20/min, temperature 37.7C, and SpO2 (arterial oxygen saturation) 95%. The laboratory data at admission: hemoglobin 13.8 g/dL, white blood cell 7.16x109/L, platelets 204x109/L, and high-sensitive C-reactive protein 0.8 mg/L (<3.0 mg/L).
Chest computed tomography (CT) showed nodularity, irregularity, and stenotic changes in the mucosa with areas of ossification throughout the tracheal lumen as well as in both main bronchi (Fig. 1). Emphysematous changes were observed throughout the lung. Faint ground-glass opacity (GGO), mild reticulation, and honeycombing cystic changes were observed in the subpleural area of both lower lobes (Fig. 2A). Two years later, follow-up CT showed interval increased extent of honeycombs, subpleural reticulation, and GGO in both lower lobes, indicating progression of ILD (Fig. 2B).
Flexible bronchoscopy was performed for a tracheal biopsy and to evaluate ILD. The biopsy findings for the trachea showed calcification in the mucosa and ossification in the submucosa (Fig. 3A). The histological examination was consistent with TPO. An analysis of the BAL fluid showed a total white blood cell area of 220 mm3, including 13% neutrophils, 13% lymphocytes and 71% macrophages.
For the diagnosis, we performed a surgical lung biopsy, and the results showed diffuse interstitial fibrosis with focal fibroblastic proliferation and lymphocytic infiltration, suggesting possible usual interstitial pneumonia. Four years after the initial presentation, the patient was re-admitted with symptoms of cough. The previously noted multifocal honeycombs and subpleural reticulations were aggravated on chest CT. We performed flexible bronchoscopy again. There were no microorganisms identified. Compared with the previous findings, the lesions of TPO throughout the tracheal lumen had also progressed (Fig. 3B).
At the time of the diagnosis, CT showed mild subpleural reticulation, ground-glass opacity and bronchiectasis in the left lower lobe medial basal segment (A).