Interstitial growth as an aggressive growth pattern in primary lung cancer

Purpose Interstitial growth (IG), which is defined as tumor cells continuously growing into the alveolar septa at the tumor periphery, was originally reported as a growth pattern of metastatic sarcoma of the lung. On the other hand, IG in the primary lung cancers has not been well described. This study aimed to examine clinicopathological features of primary lung cancer that harbors IG.