High-resolution computed tomography and histopathological findings in hypersensitivity pneumonitis: a pictorial essay

• Main Author: Torres,Pedro Paulo Teixeira e Silva
• Publication Date: 2016
• Other Authors: Moreira,Marise Amaral Rebouças, Silva,Daniela Graner Schuwartz Tannus, Gama,Roberta Rodrigues Monteiro da, Sugita,Denis Masashi, Moreira,Maria Auxiliadora do Carmo
• Format: Article
• Language: eng
• Source: Radiologia Brasileira (Online)
• Download full: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0100-39842016000200012
• topic: Alveolitis, extrinsic allergic/pathology; Tomography, X-ray computed; Lung diseases, interstitial

Abstract Hypersensitivity pneumonitis is a diffuse interstitial and granulomatous lung disease caused by the inhalation of any one of a number of antigens. The objective of this study was to illustrate the spectrum of abnormalities in high-resolution computed tomography and histopathological findings related to hypersensitivity pneumonitis. We retrospectively evaluated patients who had been diagnosed with hypersensitivity pneumonitis (on the basis of clinical-radiological or clinical-radiological-pathological correlations) and had undergone lung biopsy. Hypersensitivity pneumonitis is clinically divided into acute, subacute, and chronic forms; high-resolution computed tomography findings correlate with the time of exposure; and the two occasionally overlap. In the subacute form, centrilobular micronodules, ground-glass opacities, and air trapping are characteristic high-resolution computed tomography findings, whereas histopathology shows lymphocytic inflammatory infiltrates, bronchiolitis, variable degrees of organizing pneumonia, and giant cells. In the chronic form, high-resolution computed tomography shows traction bronchiectasis, honeycombing, and lung fibrosis, the last also being seen in the biopsy sample. A definitive diagnosis of hypersensitivity pneumonitis can be made only through a multidisciplinary approach, by correlating clinical findings, exposure history, high-resolution computed tomography findings, and lung biopsy findings.