Correlation between high-resolution computed tomography appearance and histopathological features in the diagnosis of interstitial lung diseases. A real-life study

BACKGROUND: According to current guidelines, a surgical biopsy is rarely required when a high-confidence radiologic interstitial lung disease (ILD) diagnosis is made on thin-section high-resolution computed tomography (HRCT). Nevertheless, disowning HRCT scans diagnosed by biopsy are more common than presumed. Our study aimed to describe the concordance rate between HRCT scans and pathological diagnoses of ILDs obtained by surgical biopsy. The current guideline suggests the use of surgical lung biopsy (SLB) in patients with newly detected ILD of unknown cause.METHODS: Patients who underwent mini-invasive surgical biopsies for interstitial lung diseases from January 2018 to August 2022 were analyzed. The HRCT scans were reviewed by an observer blinded to the patient's clinical information. The concordance between histological and HRCT-scan were assessed.RESULTS: Data from 104 patients with uncertain low confidence diagnosis of interstitial lung diseases at HRCT were analyzed. Most of the patients are male (65; 62.5%). The more frequent HRCT pattern were: alternative diagnoses (46; 44.23%), UIP probable (42; 40.38%), UIP indeterminate (7; 6.73%), and non-specific interstitial pneumonia (NSIP) (9, 8.65%). The more common histological diagnosis was UIP definite (30; 2 8.84%), hypersensitivity pneumonia [HP](19; 18.44%), NSIP (15; 14.42%), sarcoidosis (10; 9.60%). In 7 (20%) cases, the final pathological finding denies HRCT-scans diagnoses; indeed, a moderate agreement was observed between HRCT-scan findings and the definitive histological diagnosis (kappa index: 0.428).CONCLUSIONS: HRCT-scan has limitations if the objective is to define interstitial lung diseases accurately. Consequently, pathological assessment should be taken into account in order to provide more accurate tailored treatment strategies because the risk is to wait from 12 to 24 months to ascertain if the ILD will be treatable as progressive pulmonary fibrosis (PPF). Undeniably true, video-assisted surgical lung biopsy (VASLB) with endotracheal intubation and mechanical ventilation is associated with a risk of mortality and morbidity that is far from nil. Nevertheless, in recent years a VASLB approach performed in awake subjects under loco-regional anesthesia (awake-VASLB) has been suggested as an effective method to obtain a highly confident diagnosis in patients with diffuse pathologies of the lung parenchyma.