EPSTEIN-BARR VIRUS-ASSOCIATED LYMPHOEPITHELIOMA-LIKE INTRAHEPATIC CHOLANGIOCARCINOMA: A CASE REPORT AND LITERATURE REVIEW

Abstract

Objective To investigate the pathological features of Epstein-Barr virus (EBV)-associated lymphoepithelioma-like intrahepatic cholangiocarcinoma (EBVaLELICC), and to improve the understanding of this disease in clinical practice. Methods Clinical and pathological data were collected from one patient with EBVaLELICC, and immunohistochemistry, in situ hybridization, and gene rearrangement test were performed for the paraffin-embedded tissue sample of this patient. The pathological features of this disease were analyzed, and a literature review was performed. Results The female patient, aged 56 years, had the tumor located in the left lateral lobe of the liver, with a clear boundary and a size of 1.8 cm×1.5 cm×1.2 cm. The patient underwent laparoscopic left lateral segment liver resection in Department of Hepatobiliary Surgery. Postoperative pathology showed that tumor cells had a glandular tubular structure, and some cells had an irregular, fused or sieve-like shape, with large nuclei, fine chromatin, small nucleoli, and no mitotic figures; proliferation of lymphocytes and plasma cells was observed with the formation of lymphoid follicles in the stroma. Immunohistochemical staining showed that CK7, CK19, and P53 had an expression rate of 10% in tumor cells, with wild type and a Ki-67 proliferation index of 5%; stromal lymphocytes showed the expression of CD3, CD4, CD8, and CD20, lymphoid follicular germinal center cells showed the expression of BCL-6 and CD10 and had no expression of BCL-2, and plasma cells showed the expression of CD38, Kappa, and Lambda; PD-L1 (22C3) was expressed in both tumor cells and interstitial lymphocytes, with a combined positive score of 30. EBER in situ hybridization assay showed diffuse positivity of tumor cells. Polymerase chain reaction detected multiple clones of lymphocyte immunoglobulin and T cell receptor genes. The patient did not receive any treatment before and after surgery and was alive after 8 months of follow-up, without tumor recurrence or metastasis. Conclusion EBVaLELICC is a rare subtype of cholangiocarcinoma with unique pathological features. Patients can benefit from immunotherapy, and EBVaLELICC tends to have a better prognosis than common cholangiocarcinoma.

Keywords

• herpesvirus 4, human|cholangiocarcinoma|immunohistochemistry|diagnosis, differential|b-lymphocytes|t-lymphocytes