Benign lymphoepithelial tumor of the pituitary.

Here, we report a case of lymphoepithelial tumor that developed in the sellar and suprasellar regions in a 56-year-old woman. The lesion was composed of abundant but benign squamous cell nests (Erdheim's nests) and heavy lymphoid tissue with well-developed lymphoid follicles. Therefore, it mimicked tonsil or adenoid tissue, but was disorganized. We report this case to define the pathogenesis and proper diagnostic terminology of this unusual sellar and suprasellar lesion, and we assume that its origin is the infundibulum.