PIK3CA and p53 Mutations by Next Generation Sequencing in Lymphoepithelioma-Like Carcinoma of the Endometrium

Lymphoepithelioma-like carcinoma of the endometrium is a very rare variant of endometrial carcinoma characterized by syncytial nests of pleomorphic epithelial cells and heavy infiltration of the stroma by lymphocytes (in particular CD8 cytotoxic T-lymphocytes) and plasma cells. Until now, only five cases have been characterized in this location. This report describes the clinicopathological and the molecular features of this unusual tumor. In particular, using the next generation sequencing (NGS) technique, we have demonstrated that this tumor could be associated with PIK3CA and p53 gene mutations. These data have not been reported to date and suggest that lymphoepithelioma-like carcinoma of the endometrium shares common molecular features with high grade endometrioid and serous-like endometrial carcinoma which are associated with poor outcome. Nevertheless, in endometrial lymphoepithelioma-like carcinoma, the alterations on cell cycle, apoptosis, and/or senescence secondary to p53 mutations could potentially be counterbalanced by the antitumoral response induced by CD8 cytotoxic T-lymphocytes numerous in these tumors.