CT-pathologic correlation in the tumor margins of lung cancer

A CT-pathologic correlative study concerning the nature of the tumor margin was performed in 22 lung cancer cases with solitary nodules in the peripheral lung field. Three of 14 adenocarcinoma cases showed an ill-defined margin and an adjacent subtle high attenuation area on CT, representing alveoli lined by tumor cells. In the other 11 cases, both ill- and well-defined margins were seen on CT. A well-defined margin of the mass represented alveoli filled entirely with mucinous material or tumor cells. In three of six squamous cell carcinomas an ill-defined margin in CT represented the infiltration of lymphatic cells surrounding the tumor and continuous spread of tumor cells from neighboring alveoli. A well-defined margin in the other cases and two small cell carcinoma cases represented alveoli filled entirely with tumor cells. CT was shown to be very useful in the assessment of the nature of the margin of the tumor.