S-lOO-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 lymphoproliferative disorder, characterized by clinically aggressive behavior, with leukemic dissemination and death within 1 year of the onset of symptoms. The neoplastic cells had abundant amphophilic cytoplasm, suggestive 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 demonstrated β-chain T-cell receptor gene rearrangement, further confirming the T-cell nature of this disorder. This case had futures very similar to those of the seven cases previously reported