Lymphoepithelioma-like carcinoma of the breast: lack of evidence of Epstein-Barr virus infection.

AIMS: Six cases of lymphoepithelioma-like carcinomas of the breast were studied in order to better define the morphology of this type of breast tumour and to see if these neoplastic lesions are related to Epstein-Barr virus (EBV) infection by analogy with histologically similar tumours located in other organs. METHODS and RESULTS: The cases were studied with immunohistochemistry using several antibodies and with in-situ hybridization method employing different types of nucleotides in four cases. The cases presented the distinctive morphology of the lymphoepithelioma-like carcinomas as seen in other organs. Specifically Rigaud and Schminke's patterns of growth were observed. In addition, at the edge of the neoplastic lesions, a lymphoepithelial lobulitis was seen. In-situ hybridization failed to reveal any positivity for EBV genome. CONCLUSION: Lymphoepithelioma-like carcinoma is a specific type of breast tumour, but its relation to EBV has yet to be proven. The differential diagnosis with medullary carcinoma is discussed.