S-100-POSITIVE T-CELL LYMPHOPROLIFERATIVE DISORDER - A CASE-REPORT AND REVIEW OF THE LITERATURE

The authors describe a patient with a S-100-positive T-cell lymphoprol iferative disorder, characterized by clinically aggressive behavior, w ith leukemic dissemination and death within 1 year of the onset of sym ptoms. The neoplastic cells had abundant amphophilic cytoplasm, sugges tive of plasmacytoid differentiation, but demonstrated a mature T-cell immunophenotype characteristic of the suppressor-cytotoxic subset. In addition, the cells expressed the S-100 protein within the cytoplasm. Genotypic studies were performed by Southern blot analysis, which dem onstrated beta-chain T-cell receptor gene rearrangement, further confi rming the T-cell nature of this disorder. This case had features very similar to those of the seven cases previously reported. It has been p roposed that the S-100-positive T-cell lymphoproliferative disorder is a distinctive clinicopathologic entity.