Clinico-pathological And Prognostic Features Of Primary Pulmonary Lymphoepithelioma-Like Carcinoma

ObjectivePrimary pulmonary lymphoepithelioma-like carcinoma is a scarce disease,thus it is prone to undiagnosis and misdiagnosis as the unfamiliarity with it.This study aim to summarize the clinico-pathological,imaging and genetic characteristics of primary pulmonary LELC,analyze factors related to lymphatic metastasis and prognosis,deepen the understanding of this rare entity,which is helpful for clinical diagnosis and prognosis evaluation.MethodsWe retrospectively evaluated the primary pulmonary lymphoepithelioma-like carcinoma patients admitted in our hospital from June 2009 to March 2017.We gathered the clinico-pathological materials,sent samples for gene detection,summarized the clinico-pathological,imaging,genetic and immunohistochemical characteristics and followed up all the included patients to further calculate prognostic factors.Result23 patients were included in this study,male-dominated(65.2%),smokers accounting for 43.4%,with a median age of 59.Cough and expectoration were the most common symptoms(39.1%),followed by chest pain(21.7%).Radiographically,lesions appeared mainly as peripheral(66.7%)masses,near to mediastinum,with inhomogeneous density(66.7%),irregular border(72.2%),lobulated or spicula sign,some also with obstructive pneumonia(27.8%)or pleural effusion.The maximum diameter was 2.99 cm in average.Contrast chest CT revealed inhomogeneous enhancement.In immunohistochemical staining,p63,CK(pan),CK14 and CK5/6 were mainly positively expressed,and the negative ones were CgA,Syn,CK7,TTF1,CD56 and CD5.It showed out 87.5%positive rate of EBER by situ hybridization(14/16).14 samples were sent for gene detection(EGFR,KRAS7,PIK3CA and BRAF),while just one showed EGFR 20 mutation.Among 22 patients underwent surgery,5 patients appeared recurrence and metastasis,half received adjuvant therapy after operation.Lymphatic metastasis related factors included younger age(p=0.008),bronchus involvement radiographically(p=0.041).And younger age,tumor necrosis(p[PFS]=0.023,p[OS]=0.005)and lymphatic metastasis showed poorer prognosis.ConclusionIt demonstrates the association between primary pulmonary LELC and EBV infection.In chest CT scan,it appears commonly as a peripheral mass,solitary,near to mediastinum,with inhomogeneous density and irregular border,and the risk of lymph node metastasis is higher if bronchus involved.Contrast chest CT often reveals inhomogeneously slight to moderate enhancement.Surgery-based multimodality treatment is recommended.And younger age(<60ys),lymph node metastasis and tumor necrosis indicate poor prognosis.