To investigate the CT imaging features and clinical manifestations of primary pulmonary sarcomatoid carcinoma, and to improve the understanding of the disease.

The clinical data and CT imaging features of 15 cases of primary pulmonary sarcomatoid carcinoma confirmed by pathology in our institute from January 2011 to September 2020 were retrospectively analyzed.

Among 15 patients with primary pulmonary sarcomatoid carcinoma, it was more common in middle-aged and elderly men over 50 years of age with a history of smoking. The clinical manifestations were cough, expectoration and blood in sputum. Each of the cases was single tumor, with 9 cases of lesions located in the right lung and 6 cases in the left lung. The upper lobes of both lungs were mostly; the maximum diameter of the tumors ranged from 12mm to 159mm, with an average of 63mm; the number of central and peripheral types were 6 cases, 9 cases, respectively; 7 cases of round shape, 3 cases of oval shape, 4 cases of irregular shape, 1 case of wedge shape; 6 lesions of relatively clear edge, 10 cases of lobes and 3 cases of burrs; 6 cases of uniform density and 9 cases of heterogeneity, including 3 cases with calcification and 1 case with irregular worm-like cavities; CT enhanced scan of 12 cases in this group, including 1 case with more uniform enhancement and 11 cases with heterogeneity enhancement; in arterial phase, peripheral area of the lesion showed ring-shaped enhancement, and performed partly showed different degrees of progressive enhancement in venous phase; the central area of the lesion often showed lightly enhancement and no significantly enhancement 9 cases or uneven patchy and divided enhancement 2 cases. 5 cases of pulmonary vascular invasion; bronchial stenosis with obstructive inflammation 9 cases, obstructive atelectasis 2 cases; 11 cases of pleural invasion, 5 cases of pulmonary hilar lymphadenopathy, 5 cases of mediastinal lymphadenopathy; internal and external lung metastases 5 cases.

Primary pulmonary sarcomatoid carcinoma mostly occurs in male patients with long-term heavy smoking. The upper lobes and peripheral types of both lungs are more common, the tumors are larger, and the density is heterogeneity. It is easy to invade the adjacent pleura, often with mediastinum and pulmonary hilar lymphadenopathy, CT enhancement has certain characteristic features, but the diagnosis still needs to rely on pathological examination.