Apoptotic and proliferating cells in cutaneous lymphoproliferative diseases.

Background: The cell production vs the cell loss rate in one of the most important parameters in evaluating growth and biological behavior of neoplasms. Individual cell disintegration in tissues, apoptosis, is a constant finding in various tumors and has been shown, by using several techniques, as a recognizable cell death that is different from necrosis.
Design: We studied the apoptosis-proliferation ratio in various lymphoproliferative disorders in the skin, including mycosis fungoides (MF), cutaneous T-cell lymphoma showing solid tumor mass (CTCL), B-cell lymphoma of the skin (BCL), lymphomatoid papulosis (LyP), and cutaneous pseudolymphoma by using terminal deoxyuridine triphosphate (dUTP)-biotin nick end labeling (TUNEL), a newly developed method to detect internucleosomal breaks characteristic of apoptotic cells.
Setting: University referral center.
Patients: Fifty patients with cutaneous lymphoproliferative diseases.
Main Outcome Measures: Proliferation indexes and apoptosis index calculated by using immunohistochemical techniques.
Results: The proliferation indexes in pseudolymphoma, which were calculated by using immunohistochemical analyses with anti-proliferating cell nuclear antigen and anti-MIB-1 monoclonal antibodies, were significantly lower than the indexes of MF, CTCL, BCL, and LyP, whereas, the apoptosis index in Lyp was significantly higher than in any other lymphoproliferative diseases studied. The apoptosis-proliferation ratio in the tumor stage of MF, CTCL, and BCL was almost constant, but the ratios in LyP and the plaque stage of MF were significantly higher than in the other diseases studied.
Conclusions: The clinical behavior of each lymphoproliferative disease in the skin seemed to be reflected in the apoptosis and proliferation indexes. We conclude that these indexes may become useful factors in the determination of the diagnosis and the prognosis for patients with lymphoproliferative diseases.