Lymphoepithelioma-like gastric cancer in Colombia: case reports and literature review.

Abstract

Lymphoepithelioma-like gastric cancer (LELGC) is a rare subtype of gastric carcinoma associated with Epstein-Barr virus infection. Although it can manifest as a large tumor mass, it has been reported to have a more favorable prognosis compared to other subtypes. Most of the available evidence comes from Asian countries, with few reports in Latin America.

This article describes three cases of patients with a histopathological diagnosis of CGLEL, all confirmed by in situ hybridization for Epstein-Barr coding RNA. Of these, two patients presented with relapse and disease progression, which led to the evaluation of PD-L1 expression and the initiation of immunotherapy treatment, with favorable clinical responses. The third patient is currently disease-free. Although LECGC can mimic other subtypes of gastric carcinoma in imaging studies, histopathological findings are essential for establishing an accurate differential diagnosis and guiding the appropriate therapeutic approach.

Introduction

Lymphoepithelioma-like gastric cancer (LELGC) is a rare subtype of gastric carcinoma, first described in 1976 by Watanabe et al. as a gastric carcinoma with lymphoid stroma. It is most commonly located in the upper and middle portions of the stomach, with a higher prevalence in men[^3,^4]. In general, it is considered a carcinoma with a good prognosis, partly due to a significant proportion of diagnoses made before metastatic involvement; however, it remains a relatively rare neoplasm.

A retrospective real-world study conducted between 2005 and 2019 in five cancer centers in China included 770 patients with lymphoepithelioma-like carcinomas (LELC), of whom 16 cases were identified as having a primary gastric tumor, corresponding to a prevalence of 2.1%. In contrast, information on this entity in Latin America is scarce.

Several types of carcinomas have been associated with infection by Epstein-Barr virus (EBV), a lymphotropic virus, including undifferentiated nasopharyngeal carcinoma, Hodgkin’s lymphoma, and Burkitt’s lymphoma. In the case of gastric carcinoma, an association with EBV has been identified in 7.0–10.0% of cases, depending on the histological type, with a higher frequency in tumors with microsatellite instability and lymphocyte-rich phenotypes. Up to 80.0% of cases of CGLEL are associated with EBV infection, with a higher frequency observed in men, in tumors of proximal location, and with diffuse histology, although the latter association is not conclusive. However, cases of EBV-negative CGLEL with microsatellite instability have also been documented.

Radiologically, this neoplasm may appear on tomography as focal thickening of the mucosa, marked thickening of the gastric wall evident with contrast, or as a bulky mass.

Regarding treatment, no specific guidelines have been designed for this subtype, so it is generally managed similarly to conventional gastric adenocarcinoma, with D2 lymphadenectomy being the surgical strategy of choice.

Varios tipos de carcinomas se han asociado con infección por virus de Epstein-Barr (VEB), un virus linfotrópico, entre ellos el carcinoma nasofaríngeo desdiferenciado, el linfoma de Hodgkin y el linfoma de Burkitt. En el caso del carcinoma gástrico, se ha identificado su asociación con VEB en el 7,0–10,0% de los casos, dependiendo del tipo histológico, con mayor frecuencia en tumores con inestabilidad microsatelital y fenotipos ricos en linfocitos. Hasta el 80,0% de los casos de CGLEL están asociados con infección por VEB, observándose una mayor frecuencia en hombres, en tumores de localización proximal y con histología de tipo difuso, aunque esta última asociación no es concluyente; Sin embargo, también se han documentado casos de CGLEL negativos para VEB, con inestabilidad de microsatélites.

Radiológicamente, esta neoplasia puede presentarse en la tomografía como un engrosamiento focal de la mucosa, un engrosamiento marcado de la pared gástrica evidenciado con contraste o como una masa voluminosa.

En cuanto al tratamiento, no se han diseñado guías específicas para este subtipo, por lo que, en general, se maneja de manera similar al adenocarcinoma gástrico convencional, siendo la linfadenectomía tipo D2 la estrategia quirúrgica de elección.

3 Clinical Oncology Unit, National Cancer Institute, Bogotá, D.C., Colombia.

4 Clinical Oncology Service, San Ignacio University Hospital, Bogotá, D.C., Colombia.

5 Faculty of Medicine, Pontificia Universidad Javeriana, Bogotá, D.C., Colombia. 6 Oncology Pathology Group, National Cancer Institute, Bogotá, D.C., Colombia.

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