Cutaneous lymphadenoma: a case report and immunohistochemical study.

Cutaneous lymphadenoma is a rare neoplasm, and characterized by a florid mononuclear cell infiltration that appears to be an integral component of the tumor. Several reports suggested that these infiltrated lymphocytes mainly consist of T cells and Langerhans cells, but no detailed phenotypical analysis of these cells has been demonstrated yet. In this report, we describe a 70-year-old Japanese patient with cutaneous lymphadenoma. In the present case, we investigated the immunohistochemical profiles of tumor-infiltrating cells in cutaneous lymphadenoma, especially focusing on the profiles of T cell subsets. In addition, there are abundant mucin deposits within the tumor stroma, and tumor lobules are composed of BerEP4-positive cells. To the best of our knowledge, this is the first report that employed immunohistochemical staining of cutaneous lymphadenoma to verify the types of cells composing such tumors with special focus on the profiles of the T cell subsets.