Cutaneous lymphoepithelial neoplasms.

Lymphoepithelial neoplasms are a heterogeneous group of biphasic tumors that contain both epithelial and lymphoid components. Most of these tumors are primarily epithelial with a secondary lymphoid infiltrate and illustrate the basic cell trafficking that occurs in the skin. Included are benign cutaneous lymphadenoma, malignant lymphoepithelioma-like carcinoma, heterotopic dermal thymus, and several miscellaneous lesions that may have a prominent lymphoid infiltrate. Familiarization with their characteristic features will aid in the recognition of these relatively uncommon but often distinct entities.