Idiopathic pulmonary fibrosis in a smoker with indeterminate usual interstitial pneumonia pattern on high-resolution computed tomography

History of present illness

A 73-year-old Caucasian man was referred to the respiratory unit complaining of worsening exertional dyspnea and productive cough, lasting for about 4 months.

Following an acute bronchitis, the primary care physician heard fine crackles on chest auscultation. He requested a chest radiography, which showed bilateral basal interstitial thickening.

Past medical history

The patient, a retired policeman, was a former smoker with a 30-pack-year smoking history, without referred exposure to noxious inhalants.

He had hypertension and type 2 diabetes. He had developed Bell’s palsy at the age of 30.

He took daily medications for hypertension (ramipril) and diabetes (metformin). His family history was negative for respiratory disease or connective tissue diseases.

Two years earlier, the patient had undergone a chest computed tomography (CT) scan, requested by the primary care physician following repeated acute bronchitis. It had revealed bibasilar subtle ground-glass opacities with fine reticulations ( Fig. 3.1 ), and a subsequent pulmonary consultation had been requested. Following a complete clinical recovery after antibiotic therapy, the patient did not undergo any other medical examination.

Fig. 3.1

Axial chest CT scan (lung parenchyma window) performed 2 years before the current presentation, showing subtle ground-glass opacities and fine reticulations at the lung bases.

Physical examination and early clinical findings

At the outpatient pulmonology visit, the patient was afebrile, alert, and cooperative. He had no peripheral edemas, whereas digital clubbing was evident. Chest auscultation confirmed inspiratory crackles in both lower lung fields. Cardiac and abdominal examinations were normal. Oxygen saturation measured by pulse oximetry (SpO 2 ) was 95% on room air, respiratory rate was 22 breaths/min, heart rate was 70 beats/min, and blood pressure was 130/80 mmHg.

Pulmonary function tests demonstrated a moderate restrictive pattern with a forced expiratory volume in 1 second (FEV 1 ) of 79% of the predicted value, forced vital capacity (FVC) of 68% of predicted, FEV 1 /FVC ratio (Tiffenau-Pinelli index) of 116%, and total lung capacity (TLC) of 67% of predicted. Diffusing capacity of the lungs for carbon monoxide (DLCO) was moderately reduced (51% of the predicted value). A slight reduction in the distance covered at the 6MWT was found (400 m, equal to 74% of predicted) but without significant oxygen desaturation (average SpO 2 92.5%, minimum SpO 2 91%).

Clinical course

A new high-resolution CT (HRCT) scan of the chest was immediately obtained. It revealed the presence of peripheral interstitial thickenings and ground-glass opacities, with basal predominance. No honeycombing was detected. Notably, a subpleural sparing was present ( Fig. 3.2 ).

Fig 3.2

Axial HRCT of the chest (lung parenchyma window) showing disease progression with interstitial thickening and ground-glass opacities, mostly located in the periphery of the lungs with basal predominance and with subpleural sparing.

A complete autoimmunity serological screening was required to rule out the presence of an underlying connective tissue disease. Antinuclear antibodies (ANAs), extractable nuclear antigen (ENA) antibodies, anti-citrulline antibodies, anti-synthetase antibodies, and rheumatoid factor were all negative.

The patient underwent a bronchoscopic examination, which showed no inspection abnormalities. Bronchoalveolar lavage (BAL) cytological analysis revealed 90% macrophages, 5% lymphocytes, 1% eosinophils, and 3% neutrophils.

A multidisciplinary discussion (MDD) was then scheduled, in the presence of pulmonologists, thoracic radiologists, a rheumatologist, and a pathologist. On the basis of the clinical case to be discussed, a thoracic surgeon was also invited.

The MDD suggested a surgical lung biopsy for an etiological diagnosis. A biopsy during awake-VATS was proposed to the patient. Surgical biopsy samples were obtained from multiple lobes (upper right lobe, middle and lower right lobe). Histopathology revealed dense fibrosis with architectural distortion, patchy fibrosis, honeycombing, and fibroblast foci. No ancillary findings suggestive of an alternative diagnosis were present. The findings were consistent with a histologic UIP pattern ( Fig. 3.3 ).

Jun 15, 2024 | Posted by in CRITICAL CARE | Comments Off on Idiopathic pulmonary fibrosis in a smoker with indeterminate usual interstitial pneumonia pattern on high-resolution computed tomography

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