Chromosomes and B and T cells in mycosis fungoides.

Because mycosis fungoides (MF) and Sézary syndrome (SS) share several features, some investigators have considered them to be different stages of the same disease. Others view them as separate entities. Cytogenetic studies in four typical MF patients showed that the chromosomal abnormalities were different from those reported in SS patients, and the abnormalities were found with almost equal frequency in both B and T cells. In addition, we found the frequencies of the T cells in six of the eight peripheral blood determinations in three patients were within normal range. These observations support the possibility that MF and SS are two separate disease entities.