To investigate the CT characteristics of primary pulmonary sarcomatoid carcinoma(PSC), and to improve the knowledge of this disease and increase the accuracy of preoperative diagnosis.

The clinical data, CT manifestations and therapeutic method of 12 patients with primary PSC confirmed by pathology from November 2013 to September 2016 in Northern Jiangsu People′s Hospital were reviewed retrospectively.

All lesions were unilateral.Eight lesions were peripheral and four lesions were central tumors, including 5 in left lung and 7 in right lung.The mean diameter of the lesions was(4.5±1.9)cm(range 0.7 to 8.6 cm). CT showed all cases presented with a spheroid solid lung mass(n=11)or nodule(n=1), and all lesions were quasi-circular, with calcification(n=1), spinous protuberance(n=5), lobulated(n=5), spicule sign(n=2), pleural invasion(n=8), mediastinal lymph nodes metastases(n=3), hilar lymph nodes metastases(n=3), osseous metastasis(n=2), left lower extremity and splenic metastasis(n=1). CT presented all cases had large neoplasms with inhomogeneous density, with a mean value of(21±14)HU(range 14 to 38 HU), which showed irregular hierarchical heterogeneous contrast enhancement after injection of contrast media.The value of high enhancement areas was(57.2±14)HU(range 47 to 60 HU), while the low attenuation was(25.3±6.3)HU(range 19 to 29 HU)(n=11). In these cases, there were 4 cases being resected by surgical operation, of which 2 patients′condition had improved, and the rest abandoned treatment.

Most cases of primary PSC appear as larger peripheral mass, and the tumor grows rapidly.CT features of primary PSC are distinctive relatively in certain extent, and all cases had large neoplasms with inheterogeneous density on the unenhanced CT films, which showed hierarchical contrast enhancement after injection of contrast media.The histopathological examination is still the most reliable way to make the final diagnosis.