Computed Tomographic and Pathological Features of Primary Pulmonary Sarcomatoid Carcinoma

To investigate the computed tomographic (CT) and pathological features of primary pulmonary sarcomatoid carcinoma (PSC).

The clinical data and CT images of 20 patients with pathologically confirmed PSC were retrospectively analyzed.

Solitary pulmonary mass was identified in 18 patients and multiple pulmonary masses in 2 patients, amounting to 22 masses. There were 17 peripheral masses and 5 central masses, including 11 masses larger than 5 cm. The smooth margin was identified in 9 masses, deep lobulation and/or spinous protuberance in 11 masses, and ill-defined margin in 2 masses. Pleural indentation was identified in 2 masses and pleural thickening with wide basement was identified in 14 masses. On plain CT, cavity was observed in 5 masses, hypo-density in 7 masses, and homogeneous density in 10 masses. On contrast-enhanced CT scanning, irregular ring/patchy enhancement were shown in 15 masses and slightly homogenous enhancement in 2 masses. Of all patients, 6 patients had unilateral or bilateral hilar and/or mediastinal lymphadenopathy. There were 16 pleomorphic carcinomas and 4 spindle cell carcinomas. Immunohistochemically, anti-pan cytokeratin antibody was positive in 13 patients, cytokeratin was positive in 8 patients, Vimentin was positive in 15 patients, epithelial membrane antigen was positive in 1 patient, and thyroid transcription factor-1 was positive in 8 patients.

PSC has some specific CT features; however, the final confirmation of PSC still depends on pathological and immunohistochemical examinations.