Adult T-cell lymphoma/leukemia in a Caribbean patient: cytogenetic, immunologic, and ultrastructural findings.

ABSTRACT

Cytogenetic findings on immunologically and morphologically characterized leukemic cells from a Caribbean patient with adult T-cell lymphoma/leukemia (ATLL) (HTLV+) are reported. Marker studies on peripheral blood lymphoid cells showed a mature postthymic phenotype TdT-, OKT3+, OKT4+, OKT6-, OKT8-, 3A1-, anti-HLA-DR-. Light and electron microscopic analysis revealed a great cellular pleomorphism with respect to nuclear features. Three main types of leukemic cell were observed typical multilobed ATLL lymphocytes, Sézary's syndrome (SS) cells, and cells intermediate between those two. Chromosome studies on PHA-stimulated cultures revealed three clones. The predominant clone was hyperdiploid; significant abnormalities were 1q+, 14q+, and 6q- (breakpoint q21), which are known to occur in lymphoid malignancies, together with trisomy 7q and i(17q), which have been reported previously in Japanese ATLL and the small variant of SS, respectively. The 14q+ marker was t(11;14)(q13;q22-24). The incidence of 6q-, trisomy 7q, and i(17q) varied within the main clone, and it is speculated that these chromosome abnormalities might be related to the variation observed in the cell types of this patient. Two minor clones had 6q- (breakpoint q25) and 13q+ markers, respectively. It was not possible to unequivocally establish the relationship between these three clones. The chromosomal, morphologic, and immunologic findings in this case support a close relationship between ATLL in Japan and in the Caribbean basin, as well as between the proliferating cells of ATLL and SS.