SEZARY CELL-LIKE LEUKEMIA WITH ATYPICAL IMMUNOPHENOTYPE

We describe the clinical and laboratory features of an unusual case wi th Sezary cell-like leukemia. Clinical manifestations were: anemia (Hb 9.4 g/dl), severe thrombocytopenia (5 x 10(9)/l), lymphocytosis (43 x 10(9)/l) and splenomegaly. There was no lymphadenopathy, hepatomegaly or skin lesions. Bone marrow trephine showed diffuse infiltration by atypical lymphoid cells. By ultrastructural analysis the cells were sm all to medium-size lymphocytes with nuclear features identical to Seza ry cells. immunophenotyping showed that most peripheral blood mononucl ear cells were negative with B lymphoid, myeloid, and stem cell-associ ated markers and were also negative with most T lymphoid markers (CD2, CD4, membrane/cytoplasmic CD3, CD5 and CD8). However, they were posit ive with CD38 (70%), CD7 (25%) and TIA-2 (25%). Molecular analysis sho wed a clonal rearrangement of the TCR beta and gamma chain genes. The patient was initially treated with vincristine, doxorubicin and aspara ginase and then with six cycles of CHOP, achieving a complete remissio n and remaining free of disease 22 months from diagnosis. Aberrant imm unophenotypes are not frequent in primary T cell leukemias. This is th e first case of a rare type of T cell neoplasm, Sezary cell-like leuke mia, in which cells lacked most of the T cell-associated antigens.