RESULTS: Multiple cavities had 4 main types of different imaging appearances, including thick-walled cavities (n=8), circular cavities (n=21), thin-walled cavities or cystic cavities (n=8), cavities or multicystic changes within airspace consolidation or ground glass opacity (n=11). The presence of internal soft-tissue septa in cavity was commonly seen (58.6%, 17/29). Those septa existed in thick-walled cavities and thin-walled cavities, seldom existed in circular cavities. Some internal septa may be like spoke sign (n=1), some may be like small vessels intruded from the wall to the inner cavity (n=6). Cavitary lesions often companied by pulmonary nodules and ground glass nodules (82.8%, 24/29). All cases were invasive adenocarcinomas (n=23) or variants of invasive adenocarcinomas (n=6). Cavities or radiolucencies within consolidation or ground glass opacity were found in all 6 invasive mucinous adenocarcinomas. Circular cavities were seen in all 4 cases of papillary adenocarcinomas.