Cytogenetic follow-up in a case of Sézary syndrome.

A cytogenetic follow-up study was performed for a 3-year period on a 70-year-old patient with Sézary syndrome (SS). The results showed formation of hypotetraploid cell clones with 60 to 89 chromosomes and 19 markers, some of which appeared during the period of study and stabilized thereafter. The incidence of these clonal cells increased from 29% to 85% during the follow-up study. The results confirm the presence of hypotetraploid cell clones, especially in the more advanced stages of SS. Moreover, some marker chromosomes in our patient (M2 and M3), derived from chromosome 2, were similar to those observed in SS by other investigators. According to our data and to those in the literature, SS appears to involve preferentially chromosomal regions 2p12-13, 2p21-22, 2q37, 17p13, 13q1, 9q11, 10p13, 14q11, 14q32, 7p1 and, to a lesser extent, 5q and 6q.