Lymphoepithelioma-like carcinoma of the breast – A case report and brief review of the literature

Abstract

Introduction: Lymphoepithelioma-like carcinoma (LELC) of the breast is a rare entity, with less than 25 cases reported in the literature. It differs from many other lymphoepithelioma-like lesions in that it lacks an association with Epstein–Barr virus (EBV). Case Report: A 67-year-old female underwent an excisional biopsy for a firm left breast mass, favoured clinically to represent fat necrosis. Pathological examination revealed a dense mixed lymphoplasmacytic population partially obscuring small groups and discohesive sheets of larger atypical cells, initially prompting suspicion of a lymphoma. Immunohistochemistry demonstrated cytokeratin positivity (AE1/3, EMA, CK7) in this atypical population whilst lymphoid markers were restricted to background inflammatory cells. EBER-ISH was negative. ER, PR and HER2 were negative. As the lesion extended to biopsy margins re-excision of margins in addition to sentinel node biopsy were performed. This demonstrated focal residual disease with no evidence of nodal metastasis. The patient remains well at the time of this report. Discussion: LELC may pose a diagnostic challenge, particularly in small biopsies. We report the clinicopathological findings in this case in conjunction with a brief review of the relevant literature.