RELATIONSHIP OF T-LEUKEMIAS WITH CEREBRIFORM NUCLEI TO T-PROLYMPHOCYTIC LEUKEMIA - A CYTOGENETIC ANALYSIS WITH IN-SITU HYBRIDIZATION

Sezary cell leukaemia (SCL) is a mature T-cell leukaemia with characte ristic cerebriform nuclei, whereas Sezary syndrome (SS) involves a mat ure T-cell lymphoma with a similar nuclear morphology, We have examine d these diseases by cytogenetics, chromosome painting and fluorescence in situ hybridization (FISH). Both diseases had complex cytogenetic a bnormalities. AU three cases of SCL investigated had inv(14)(q11;q32) and two had iso(8q). No case of SS had these abnormalities but, instea d, iso(17q) or 17p+ was present in the three cases of SS investigated and FISH indicated loss of heterozygosity due to deletion of a region at 17p13 that included the tumour suppressor gene P53, implicating it in this malignancy, One case of SCL had iso(17q). The abnormalities of chromosomes 8 and 14 in SCL are commonly observed in T-prolymphocytic leukaemia (T-PLL) and suggest that SCL may be a variant of T-PLL rath er than of SS.