Abstract: Objective: To explore the curative effect of local radiotherapy combined with epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) in the treatment of the patient with unresectable and low-grade pulmonary mucoepidermal carcinoma (PMEC) with positive EGFR mutation, to analyze the effectiveness and safety of the treatment mode, and to provide the clinical reference for the treatment of this disease. Methods: The clinical data of a patient who diagnosed as PMEC was collected. The relationships between the changes of imaging and clinical symptoms and the prognosis of the patient were analyzed and the relative literatures were reviewed. Results: A 22-year-old woman was admitted to the hospital due to shortness of breath and 2 months of cough.The pathological diagnosis was PMEC,the L858R mutation in exon 21 of EGFR gene was found by gene detection and the tumor could not be resected by surgery.The patient was treated with gefitinib 250 mg·d^-1 orally combined with radiotherapy,and the dose of radiotherapy was 50 Gy totally with 2 Gy per fraction(25 times). After the treatment of local radiotherapy combined with oral administration of gefitinib, the tumor size was shrunk compared with before radiotherapy. The tumor size was shrunk further after the intervention of continuous oral gefitinib;the patient had no adverse reactions except the mild skin rash,and the progression free survival (PFS) was 18 months. Conclusion: For the unresectable and low-grade PMEC patient with positive EGFR mutation, the treatment mode of radiotherapy combined with EGFR-TKIs has good efficacy and the side effects could be accepted.

Key words: pulmonary mucoepidermal carcinoma, epidermal growth factor receptor, mutation, gefitinib, radiotherapy, tyrosine kinse inhibitors