%0 Journal Article
%T Histopathological Implications of Aspergillus Infection in Lung
%A Naobumi Tochigi
%A Yoichiro Okubo
%A Tsunehiro Ando
%A Megumi Wakayama
%A Minoru Shinozaki
%A Kyoko Gocho
%A Yoshinobu Hata
%A Takao Ishiwatari
%A Tetsuo Nemoto
%A Kazutoshi Shibuya
%J Mediators of Inflammation
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/809798
%X This paper opens with a discussion on the significance of invasive fungal infections in advanced contemporary medicine, with an emphasis on the intractability of disease management and the difficulties of diagnosis. This is followed by a discussion concerning classification, histopathological features, and pathophysiology. While it has been largely accepted that Aspergillus species is recognized by cellular receptors and attacked by neutrophils, the radiological and macroscopic findings linking infection with neutropenia remain unconfirmed. In an effort to gain a better understanding of the pathophysiology and pathogenesis of invasive aspergillosis, we wish to emphasize the utility of radiological and histopathological examinations since these can provide detailed information on the extremely complex interaction between the causative microbes and tissue responses. A review of noninvasive or semi-invasive aspergillosis is also provided, with particular emphasis on chronic necrotizing pulmonary aspergillosis, which is recognized as a transition form of simple pulmonary aspergilloma and invasive pulmonary aspergillosis, although few findings have been reported in this area. 1. Introduction Inflammation can be understood as the defense reaction of host against injury, which varies depending on the particular agent, tissue, and individual host characteristics [1¨C4]. Accordingly, infectious disease has been regarded as an inflammatory response caused by a microorganism that acts as an injury agent. Histopathological changes occurring at the site of infection and altered tissue structures generally result from an extensively complicated interaction between the causative microbes and tissue responses. Simplifying the issue to facilitate a better understanding of the processes involved, let us define infection as a pathognomonic condition induced by the interaction of pathogens with extracellular matrices. In the case of opportunistic infections, especially those involving invasive fungal infections, tissue responses against some pathogenic fungi are lowered, although the cause and extent of the defense mechanisms vary from case to case. In this regard, the features of lesions produced by an invasion of pathogenic fungi can be understood as a phenotypic representation resulting from an interaction between invasion by the causative fungi and variously lowered defense mechanisms of the host, as observed ubiquitously through a microscope. It has generally been accepted that pulmonary aspergillosis can be divided into invasive pulmonary aspergillosis (IPA), chronic
%U http://www.hindawi.com/journals/mi/2013/809798/