The Pathology of Interstitial Pneumonia-related Lung Cancer

Abstract

Interstitial pneumonia is a progressive inflammatory disease that mainly affects the lung interstitium (alveolar septa). The essential lesions associated with this disease consist of chronic tissue injury (inflammation of the alveolar epithelium and interstitium) and fibrosis associated with its repair, which leads to reduced compliance and it tends to clinically manifest as restrictive disorders. On the other hand, pathologically, it results in tissue remodeling lesions (honeycomb lung). In general, carcinomas that develop from the background of chronic inflammatory diseases, such as inflammatory colorectal cancer occurring in inflammatory bowel disease, renal cancer associated with acquired cysts occurring in chronic renal disease or end-stage kidney disease, and hepatocellular carcinoma occurring in chronic hepatitis, often show distinctive characteristics. In this review, I will discuss the histopathological characteristics, histogenesis (carcinogenic factors and precancerous lesions), molecular genetic characteristics, and clinical problems (and our efforts to solve them) associated with interstitial pneumonia-related lung cancer.