Volume 35, Number 1
February 2014
Letter From the Guest Editor: Interstitial Pneumonia and Related Disorders
T
he current issue of Seminars in Ultrasound, CT, and MRI reviews on key topics in pulmonary radiology applied to interstitial pneumonia and related disorders. Although interstitial pneumonia is one of the most important problems among diffuse infiltrative pulmonary disorders, it is extremely heterogeneous. Liebow and Carrington first described the concept of interstitial pneumonia in the 1960s and proposed the following histologic classifications: usual interstitial pneumonia (UIP); bronchiolitis obliterans interstitial pneumonia and diffuse alveolar damage (DAD); desquamative interstitial pneumonia; lymphocytic interstitial pneumonia; and giant cell interstitial pneumonia. Thereafter, a few new diseases have been proposed, including bronchiolitis obliterans organizing pneumonia, acute interstitial pneumonia, respiratory bronchiolitis–associated interstitial lung disease, nonspecific interstitial pneumonia (NSIP), and combined pulmonary fibrosis and emphysema. To avoid confusion, the American Thoracic Society and the European Respiratory Society jointly published the International Multidisciplinary Consensus Classification of the Idiopathic Interstitial Pneumonias in 2002 and updated it in 2013. Although computed tomography (CT) was introduced in respiratory medicine in the 1980s, the importance of high-resolution CT (HRCT) has been increasing for the past 3 decades. Our group in Japan was among the early adopters of HRCT for diffuse parenchymal lung diseases. Thinking back to those days, I feel as if I were living in quite a different world. The lung parenchyma is ideal for evaluation by HRCT. In the opening article, Kazuhiro Tabata and Junya Fukuoka review histopathologic features of UIP and related patterns in HRCT diagnosis. This histologic review is valuable because it is addressed specifically to the radiologist. I believe that the schematic views provided here would make great contributions to the understanding of radiologic-pathologic correlation. In the next article, David Lynch and Jason Huckleberry from National Jewish Health review typical and atypical HRCT features. It is important to be familiar with the typical and atypical HRCT appearances of UIP because the presence of a UIP pattern on HRCT is key in establishing the diagnosis of idiopathic pulmonary fibrosis. We also appreciated considering the hypothesis that HRCT features can be a substitute for histologic views in a diagnosis of UIP pattern. The third article by Takeshi Johkoh focuses primarily on NSIP and discusses
0887-2171/$ - see front matter & 2014 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1053/j.sult.2013.10.002
the differentiation between UIP and NSIP patterns in HRCT views. This topic would particularly intrigue the clinician who may wonder if a radiologist can be relied on to provide a decisive indication for surgical lung biopsy. The focus of the next review by Bryson, Sundaram, Khanna, and Kazerooni from the University of Michigan Health System, Ann Arbor, is on connective tissue disease–associated interstitial pneumonia. Although HRCT plays a central role in diagnosing interstitial pneumonia, features of interstitial lung diseases overlap among systemic diseases and with idiopathic entities. Their review may possibly answer the important question of whether radiologists can contribute to the differentiation between connective tissue disease–associated interstitial pneumonia and idiopathic interstitial pneumonia. Kazuya Ichikado provides an in-depth review of the histopathologic and radiologic features of DAD, such as acute respiratory distress syndrome, acute interstitial pneumonia, and acute exacerbation of idiopathic pulmonary fibrosis. We could learn a lot from his HRCT-pathologic correlation in DAD. Yeon Joo Jeong, Kyung Soo Lee, and their colleagues present a summary of HRCT appearance observed in 2 granulomatous lung disorders, chronic hypersensitivity pneumonitis and pulmonary sarcoidosis, and offer an outstanding discussion on the role of HRCT in differentiating UIP patterns. These articles are followed by an excellent review by Arjun Nair and David M. Hansell describing the HRCT features of less common types of interstitial pneumonia, that is, smoking-related interstitial lung disease, including desquamative interstitial pneumonia, respiratory bronchiolitis–associated interstitial lung disease, and pulmonary Langerhans cell histiocytosis. All of the authors who contributed to this issue are widely recognized experts in pulmonary radiology. I thank them for their outstanding and valuable contributions to this issue. It was my pleasure to participate in facilitating this issue of Seminars and I hope that readers find the articles interesting and informative. I would also like to thank Dr Howard W. Raymond for giving me this opportunity to serve as guest editor and Ms Dana Roth for her ongoing support and assistance.
Koichi Nishimura, MD Guest Editor 1
February 2014
Letter From the Guest Editor: Interstitial Pneumonia and Related Disorders
T
he current issue of Seminars in Ultrasound, CT, and MRI reviews on key topics in pulmonary radiology applied to interstitial pneumonia and related disorders. Although interstitial pneumonia is one of the most important problems among diffuse infiltrative pulmonary disorders, it is extremely heterogeneous. Liebow and Carrington first described the concept of interstitial pneumonia in the 1960s and proposed the following histologic classifications: usual interstitial pneumonia (UIP); bronchiolitis obliterans interstitial pneumonia and diffuse alveolar damage (DAD); desquamative interstitial pneumonia; lymphocytic interstitial pneumonia; and giant cell interstitial pneumonia. Thereafter, a few new diseases have been proposed, including bronchiolitis obliterans organizing pneumonia, acute interstitial pneumonia, respiratory bronchiolitis–associated interstitial lung disease, nonspecific interstitial pneumonia (NSIP), and combined pulmonary fibrosis and emphysema. To avoid confusion, the American Thoracic Society and the European Respiratory Society jointly published the International Multidisciplinary Consensus Classification of the Idiopathic Interstitial Pneumonias in 2002 and updated it in 2013. Although computed tomography (CT) was introduced in respiratory medicine in the 1980s, the importance of high-resolution CT (HRCT) has been increasing for the past 3 decades. Our group in Japan was among the early adopters of HRCT for diffuse parenchymal lung diseases. Thinking back to those days, I feel as if I were living in quite a different world. The lung parenchyma is ideal for evaluation by HRCT. In the opening article, Kazuhiro Tabata and Junya Fukuoka review histopathologic features of UIP and related patterns in HRCT diagnosis. This histologic review is valuable because it is addressed specifically to the radiologist. I believe that the schematic views provided here would make great contributions to the understanding of radiologic-pathologic correlation. In the next article, David Lynch and Jason Huckleberry from National Jewish Health review typical and atypical HRCT features. It is important to be familiar with the typical and atypical HRCT appearances of UIP because the presence of a UIP pattern on HRCT is key in establishing the diagnosis of idiopathic pulmonary fibrosis. We also appreciated considering the hypothesis that HRCT features can be a substitute for histologic views in a diagnosis of UIP pattern. The third article by Takeshi Johkoh focuses primarily on NSIP and discusses
0887-2171/$ - see front matter & 2014 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1053/j.sult.2013.10.002
the differentiation between UIP and NSIP patterns in HRCT views. This topic would particularly intrigue the clinician who may wonder if a radiologist can be relied on to provide a decisive indication for surgical lung biopsy. The focus of the next review by Bryson, Sundaram, Khanna, and Kazerooni from the University of Michigan Health System, Ann Arbor, is on connective tissue disease–associated interstitial pneumonia. Although HRCT plays a central role in diagnosing interstitial pneumonia, features of interstitial lung diseases overlap among systemic diseases and with idiopathic entities. Their review may possibly answer the important question of whether radiologists can contribute to the differentiation between connective tissue disease–associated interstitial pneumonia and idiopathic interstitial pneumonia. Kazuya Ichikado provides an in-depth review of the histopathologic and radiologic features of DAD, such as acute respiratory distress syndrome, acute interstitial pneumonia, and acute exacerbation of idiopathic pulmonary fibrosis. We could learn a lot from his HRCT-pathologic correlation in DAD. Yeon Joo Jeong, Kyung Soo Lee, and their colleagues present a summary of HRCT appearance observed in 2 granulomatous lung disorders, chronic hypersensitivity pneumonitis and pulmonary sarcoidosis, and offer an outstanding discussion on the role of HRCT in differentiating UIP patterns. These articles are followed by an excellent review by Arjun Nair and David M. Hansell describing the HRCT features of less common types of interstitial pneumonia, that is, smoking-related interstitial lung disease, including desquamative interstitial pneumonia, respiratory bronchiolitis–associated interstitial lung disease, and pulmonary Langerhans cell histiocytosis. All of the authors who contributed to this issue are widely recognized experts in pulmonary radiology. I thank them for their outstanding and valuable contributions to this issue. It was my pleasure to participate in facilitating this issue of Seminars and I hope that readers find the articles interesting and informative. I would also like to thank Dr Howard W. Raymond for giving me this opportunity to serve as guest editor and Ms Dana Roth for her ongoing support and assistance.
Koichi Nishimura, MD Guest Editor 1
