RESUMO
Purpose To study the clinicopathological characteristics,treatments and prognosis of primary pulmonary lymphoepithelioma-like carcinoma (LELC).Methods Twenty cases of LELC were collected and the clinicopathological characteristics,immunohistochemical expression,survival data and clinical treatments were analyzed,with review of the literatures.Resuits Histopathologically,it was characterized by the syncytial pattern of growing with large vesicular nuclei,conspicuous nucleoli,and a marked lymphocytic infiltrate in the stroma that was similar to undifferentiated nasopharyngeal carcinoma.The immunohistochemical staining of CKpan showed positive expression in all cases (100％).Also the positive expression of in situ hybridization of Epstein-Bar virus-encoded RNA (EBER) were in all cases (100％) while the positive cases of CK5/6,p63 and p40 were 19,18,and 16 respectively.But gene mutations such as EGFR,K-RAS were negative.All the LELC patients in this cohort were survived until the deadline of follow-up.Comprehensive treatments were done such as surgical resection,radiotherapy and chemotherapy.Conclusion Primary pulmonary LELC is a rare disease that histomorphological analysis and immunohistochemistry are the main methods of diagnosis for it.It must be excluded the metastasis carcinoma from other locations.While both EGFR mutation and anaplastic lymphoma kinase (ALK)mutation could be commonly detected in non-small cell lung cancer,but seldom in LELC of lung.The high expression of PD1/PD-L1 may provide a rationale for immunotherapy in this subtype of lung cancer.Currently,experimental therapy is still taken in the pulmonary LELC.