Features of clinical pathology and immunohistology of lymphoepithelioma-like gastric carcinoma

Abstract

Objective To analyze and summarize the clinical-pathological features,immunophenotype and prognosis of the lymphoepithelioma-like gastric carcinoma (LELGC).Methods The clinical,radiographic and histological data of four patients with LELGC were retrospectively analyzed.The expression of cytokeratin (CK),CD20,CD3,CD4,CD8,E-cadherin,β-catenin,bcl-2,p16,p53,p63,c-erbB-2,cyclin D1,Ki67 and DNA methyl-transferase 1 (DNMT1) in tumor was detected by Epstein-Barr virus-encoded small RNA (EBER) in situ hybridization and immunohistochemical methods.Results The size of four tumor was 1.8 cm× 1.6 cm,1.5 cm× 2.0 cm,2.5 cm× 2.0 cm and 4.0 cm× 2.5 cm.Under light microscope,tumor cells appeared like cords,small lumps or scattered single infiltration with vacuolized nucleus; clear nucleoli and obvious interstitial lymphocytic infiltration.The results of immunohistochemical examination indicated that in four tumors CK was positive in membrane of all the tumor cells,while EBER was positive in all cell nucleus.The number of lymphocytes with CD3 positive was over those with CD20 positive,which was mainly CD8 positive lymphocytes.The percentage of E cadherin and β-catenin positive in the cell membrane of four tumors was between 10 ％ and 90 ％,and two cases with β-catenin positive in cytoplasm.The expressions of DNMT1,cyclin D1 and bcl-2 were all positive,while p16 and c-erbB-2 were all negative.The expression of p63 was positive in only one case,and p53 was negative in one case.The percentage of Ki67 positive was 40％,15％,60％ and 40％,respectively.Conclusions LELGC is a rare neoplasm with better prognosis.The features of clinical pathology and immunohistology may help to make a correct diagnosis. Key words: Stomach neoplasms; Lymphoepithelioma like carcinoma; Immunohistochemistry; Pathology, clinical; In situ hybridization; Herpesvirus 4, human