Chromosome studies in 17 patients with the Sézary syndrome.

Chromosome studies were done on phytohemagglutinin-stimulated peripheral blood from 17 patients with Sézary syndrome. A chromosomally abnormal clone was found in five patients: each patient had an abnormal chromosome 6 and four had an abnormal chromosome 1. Six patients without abnormal clones had more than 20% metaphases with random heteroploidy and sporadic structural anomalies. Only normal metaphases were seen in four patients, and no metaphases were found in two. Four of the five patients with an abnormal clone died, and their median survival from chromosome analysis was 6 months; only one of these patients died of lymphoma. The six patients with increased heteroploidy had long survivals and no apparent malignant process. Two of the four patients with normal metaphases died of malignant disease: one had lymphoma and the other squamous cell carcinoma. A third patient with normal chromosomes died of extensive visceral cutaneous T-cell lymphoma.