RESUMO Objetivo Correlacionar a prevalência e o prognóstico de cada padrão de TCAR de pneumonia intersticial usual (PIU) típica, provável e indeterminada com o diagnóstico clínico multidisciplinar de doença pulmonar intersticial (DPI). Métodos Incluímos todos os pacientes com diagnóstico multidisciplinar de DPI com padrão de TCAR de PIU típica, PIU provável ou indeterminada para PIU. Dados clínicos e histopatológicos, teste de função pulmonar e status de sobrevida foram obtidos retrospectivamente. O diagnóstico final foi validado por uma equipe multidisciplinar. Resultados Foram incluídos no estudo 244 pacientes, com média de idade de 68 ± 13 anos sendo 52,5% do sexo masculino. Em um total de 106 pacientes com padrão típico de PIU, 62% tiveram o diagnóstico multidisciplinar de FPI, 20% de pneumonia por hipersensibilidade crônica (PHC) e 10% de DPI relacionada à doença do tecido conjuntivo (DPI-DTC). Dos 114 casos com provável PIU, DPI-DTC correspondeu a 39%, FPI a 31%, pneumonia intersticial descamativa a 11%, doença pulmonar relacionada a medicamentos a 9% e PHC a 8%. Nos 24 pacientes com TC indeterminada para PIU, o DPI-DTC foi o diagnóstico final em 33%, seguido por pneumonia intersticial descamativa (21%) e FPI (13%). Pacientes com PIU típica apresentaram maior probabilidade de morrer ou realizar transplante de pulmão no seguimento (17,9% e 11,3%, respectivamente). Conclusões FPI, PHC e DPI-DTC foram os principais diagnósticos diferenciais em pacientes com padrão de TCAR de PIU típica, provável e indeterminada. Pacientes com padrão de PIU típico na TCAR tiveram maior probabilidade de morrer ou realizar transplante de pulmão no seguimento.

ABSTRACT Objective To correlate the prevalence and prognosis of each HRCT pattern of typical, probable, and indeterminate usual interstitial pneumonia (UIP) with the clinical multidisciplinary diagnosis of interstitial lung disease (ILD). Methods We included all patients with a multidisciplinary diagnosis of ILD with an HRCT pattern of typical UIP, probable UIP, or indeterminate for UIP. Clinical and histopathological data, pulmonary function tests, and survival status were retrospectively obtained. The final diagnosis was validated by a multidisciplinary team. Results A total of 244 patients were included in the study, with a mean age of 68 ±13 years and being 52.5% males. In a total of 106 patients with typical UIP pattern, 62% had the multidisciplinary diagnosis of IPF, 20% had chronic hypersensitivity pneumonitis (CHP), and 10% had connective tissue disease-related ILD (CTD-ILD). Out of the 114 cases with probable UIP, CTD-ILD corresponded to 39%, IPF to 31%, desquamative interstitial pneumonia to 11%, drug-related lung disease to 9%, and CHP to 8%. In the 24 patients with CT indeterminate for UIP, CTD-ILD was the final diagnosis in 33%, followed by desquamative interstitial pneumonia (21%), and IPF (13%). Patients with typical UIP were more likely to die or had lung transplantation in the follow-up (17.9% and 11.3%, respectively). Conclusion IPF, CHP, and CTD-ILD were the main differential diagnoses in patients with HRCT patterns of typical, probable and indeterminate UIP. Patients with HRCT typical UIP pattern were more likely to die or had lung transplantation in the follow-up.

Idiopathic pulmonary fibrosis is a chronic disease of unknown etiology that usually has a progressive course and is commonly associated with a poor prognosis. The main symptoms of idiopathic pulmonary fibrosis, including progressive dyspnea and dry cough, are often nonspecific. Chest high-resolution computed tomography is the primary modality used in the initial assessment of patients with suspected idiopathic pulmonary fibrosis and may have considerable influence on subsequent management decisions. The main role of computed tomography is to distinguish chronic fibrosing lung diseases with a usual interstitial pneumonia pattern from those presenting with a non-usual interstitial pneumonia pattern, suggesting an alternative diagnosis when possible. A usual interstitial pneumonia pattern on chest tomography is characterized by the presence subpleural and basal predominance, reticular abnormality honeycombing with or without traction bronchiectasis, and the absence of features suggestive of an alternative diagnosis. Idiopathic pulmonary fibrosis can be diagnosed according to clinical and radiological criteria in approximately 66.6% of cases. Confirmation of an idiopathic pulmonary fibrosis diagnosis is challenging, requiring the exclusion of pulmonary fibroses with known causes, such as asbestosis, connective tissue diseases, drug exposure, chronic hypersensitivity pneumonitis, and other forms of idiopathic interstitial pneumonitis. The histopathological hallmark of usual interstitial pneumonia is a heterogeneous appearance, characterized by areas of fibrosis with scarring and honeycombing alternating with areas of less affected or normal parenchyma. The aim of this article was to review the clinical, radiological, and pathological features of idiopathic pulmonary fibrosis and of diseases that might mimic idiopathic pulmonary fibrosis presentation.