Differentiation of malignant lymphoma and non-lymphoma by an occlusive dressing method employing bromodeoxyuridine

Although lymphoma cells can proliferate in skin tissue, lymphocytes which have infiltrated the skin due to inflammatory changes are generally unable to do so. It may be possible to differentiate malignant lymphomas from benign lymphocytic infiltrations in skin tissue by detection of cell cycle-related antigens. We developed a novel in vivo method for studying the cell kinetics of human skin using bromodeoxyuridine (BrdU) with an occlusive dressing. Following the application of BrdU, BrdU-labeled lymphoid cells were counted in the dermis. The patients studied included 22 with various types of lymphomas (lymphoma group) and 22 with different forms of inflammatory skin disease (non-lymphoma group). Skin specimens were obtained after applying occlusive adhesive plasters containing 2% BrdU dissolved in 0.9% sodium chloride solution and were then immunostained with anti-BrdU monoclonal antibody. The average percentages of labeled cells were 15.9 +/- 7.6% for the lymphoma group and 4.7 +/- 2.6% for the non-lymphoma group. This difference was statistically significant (p < 0.0001). Using this method, malignant lymphomas and benign lymphocytic infiltrations of the skin could be differentiated by counting BrdU-labeled lymphoid cells, and this method could help in determining a prognosis.