Epstein-Barr virus-associated lymphoepithelial carcinoma in the pancreas.

Lymphoepithelial carcinoma is a relatively common malignancy in the nasopharyngeal region, but it rarely occurs at other sites. We report a lymphoepithelial carcinoma in the pancreas of a 65-year-old male patient operated on for a gastric stump carcinoma 7 years previously. The solitary tumor in the pancreas presented as a circumscribed lesion and measured 5.5 cm in diameter. The tumor was densely infiltrated by lymphocytes, and the neoplastic cells fulfilled all criteria for a lymphoepithelial carcinoma. Several peripancreatic lymph node metastases were observed. Marked reactivity for Epstein-Barr virus (EBV) early RNA (EBER) was detected in the majority of tumor cells using in situ hybridization. Nuclear EBER signals were also detected in the previously operated gastric stump adenocarcinoma, which also exhibited focal lymphocytic infiltration but otherwise displayed a histology different from lymphoepithelial carcinoma and did not show local recurrence. Even though an unusually late metastasis of the gastric carcinoma cannot be ruled out, we favor the hypothesis that this patient developed an EBV-related pancreatic lymphoepithelial carcinoma as a second primary tumor, based on the considerable delay of this tumor manifestation, the unusual site, the pathologic presentation, the exclusively peripancreatic nodal spread, and the different histology of the lesion.