Lymphoepithelioma-like carcinoma of head and neck skin: a systematic analysis of 11 cases and review of literature.

Lymphoepithelioma-like carcinoma of the skin (LELCS) is a rare tumor of unknown etiology, low malignant potential, and microscopic resemblance to undifferentiated nasopharyngeal carcinoma. Clinically, it presents as a flesh-colored firm nodule or plaque on the face, scalp, or shoulder of middle-aged to elderly individuals. Histologically, LELCS is composed of islands of enlarged epithelial cells with large vesicular nuclei surrounded and permeated by a dense lymphoplasmacytic infiltrate. LELCS exhibits immunoreactivity with high-molecular-weight cytokeratins and epithelial membrane antigen, indicating the epithelial origin. The differential diagnosis includes basal cell carcinoma, squamous cell carcinoma, lymphoma, pseudolymphoma, and Merkel cell carcinoma. We report 11 cases of LELCS of the head and neck region with discussion of the clinical, histopathologic, immunohistochemical, and therapeutic aspects of this rare cutaneous neoplasm. In addition, we systematically review and compare the findings with the previously published cases of LELCS. This study is the largest case series of LELCS reported in the English-language literature. It attempts to more clearly define the diagnostic criteria for LELCS. Its histomorphologic and immunophenotypic features help distinguish this tumor from similar-appearing malignancies, including metastatic nasopharyngeal carcinoma.