Cutaneous lymphoepithelioid lymphoma (Lennert's lymphoma). Combined immunohistological, ultrastructural, and DNA-flow-cytometric analysis.

Lymphoepithelioid lymphoma (LEL) is a peculiar type of low grade malignant T cell lymphoma usually arising in lymph nodes, characterized immunohistologically by predominant T-helper/inducer lymphocytes intermingled with clusters of epithelioid cells. An uncommon case of LEL with cutaneous involvement is reported with additional reference to ultrastructure and DNA-flow-cytometric analysis (DNA-FCM) of the lymphoma. Light microscopy showed subepidermal bandlike infiltrates of lymphocytes and clusters of epithelioid cells extending into the subcutaneous tissue. By immunohistochemistry the presence of a high percentage of T-helper/inducer lymphocytes was confirmed. DNA-FCM demonstrated an aneuploid cell population indicating malignant cells. Our results are in accordance with earlier ones established in lymph nodes.