Figure 1b. Radiologic findings in a 43-year-old man with a 40-pack-year smoking history who developed limited small cell carcinoma of the right lung. (a) Posteroanterior radiograph shows a relatively large mass (*) in the right lung with an enlarged right hilum (arrow). A lateral radiograph showed the same observations. (b) CT image obtained at the level of the lower hila shows the mass (*). A small component of lower subcarinal lymphadenopathy is present (arrowhead). (c) CT image obtained more cephalad shows adenopathy involving the right hilum (arrow) and subcarinal region (arrowheads). (d) CT image obtained at the level of the aortic arch shows right paratracheal lymphadenopathy (arrow). The images reveal no findings that indicate the histologic features of the malignancy. Therefore, the radiologic TNM stage of the lesion is T2 N2 M0 because the primary tumor is larger than 3 cm in diameter, mediastinal lymphadenopathy is present, and there is no evidence of other metastases.