Pulmonary sarcomatoid carcinoma (SC) consists of both carcinomatous and sarcomatous tumors with high degree of malignancy, rapid progression, and poor prognosis. However, little is known regarding how pulmonary SC develops and progresses. | Molecular genetic characterization reveals linear tumor evolution in a pulmonary sarcomatoid carcinomas patient with a novel PHF20-NTRK1 fusion A case report