Objective  To investigate the CT findings on primary pulmonary sarcomatoid carcinoma (PSC) and to improve knowledge on PSC.

  Methods  The chest CT findings and clinicopathological information on 30 patients with pathology-confirmed primary pulmonary sarcomatoid carcinoma were reviewed retrospectively.

  Results  Of the 30 tumors, 27 were peripheral, and 3 were central. The mean maximum diameter of the lesions was 5.7 cm (ranging from 3.0 cm to 9.2 cm). Ten lesions were found located in the right upper lobe, one in the right middle lobe, 8 in the right lower lobe, 7 in the left upper lobe, and 4 in the left lower lobe. Among these lesions, 13 were irregular, 12 were oval or ovoid, and 5 were shallowly or deeply lobulated. A well-defined margin was seen in 15 cases and an ill-defined margin in 14 cases. One central case had obstructive atelectasis, with ill-defined and barbed margins. A plain scan of CT demonstrated that 9 masses were homogeneous in density, and the other 21 were inhomogeneous. A cavity was seen in 6 of the total tumors and calcification in 4. After enhancement scanning for 18 cases, no enhancement or irregular patchy enhancement was found in the central part of the tumors. However, an irregular ring-like enhancement was found around the tumors. A total of 17 cases had hilar or mediastinal lymphadenectasis. Pleural or chest wall invasion was found in 12 cases, of which 5 were with adjacent bone destruction and 5 with metastasis.

  Conclusion  Although PSC has some relatively specific CT features after enhancement, the diagnosis of the disease primarily depends on the pathology.