Two cases of cutaneous lymphadenoma: a histological and immunohistological study.

The histological and immunohistological features of two cases of cutaneous lymphadenoma was studied. A single, erythematous nodule with smooth surface developed on the face of both patients. The lesion slowly progressed. Histology revealed irregular epithelial lobules in the dermis which showed a peripheral palisaded border of basaloid-like cells as well as a center composed of clear cells. Some epithelial lobules and surrounding stroma were infiltrated by numerous small lymphocytes. Immunohistological study showed that the lymphocytic infiltration was predominantly composed of T cells (CD3 positive) along with a small number of B cells (CD20 positive). Within epithelial lobules and surrounded stroma, there were numerous dendritic cells that were positive for S-100 and CD1a but negative for cytokeratin 7, cytokeratin 20 or carcino-embryonic antigen. In the center of epithelial lobules in one case, a few cells positive for epithe-lial membrane antigen and CD30 was observed. The diagnosis of cutaneous lymphadenoma was made according to the pathological and immunohistochemical findings, and the infiltration was predominated by CD3-positive lymphocytes in this uncommon epithelial neoplasm. Key words: Cutaneous lymphadenoma; Histology; immunohistological