Trisomy 8q due to i(8q) or der(8) t(8;8) is a frequent lesion in T-prolymphocytic leukaemia: four new cases and a review of the literature.
Cytogenetic abnormalities found in four cases of T-cell prolymphocytic leukaemia (T-PLL) are described. An isochromosome 8q was found in three patients and a t(8;8) in one. In the four cases, karyotypes were complex and showed a high degree of instability. In addition, we reviewed 27 published cases of cytogenetically studied T-PLL. On the whole, the most frequently recurring anomalies in T-PLL are 14q lesions with nonrandom breakpoints, inversion (14)(q11q32) or tandem translocations (14;14) (not seen in any of our cases) and trisomy for 8q. mainly due to i(8q), found in more than 40% of patients each. Similar structural anomalies were found almost as frequently among the 23 cytogenetically studied cases of so-called T-chronic lymphocytic leukaemia (T-CLL) reported prior to 1989. It is now accepted that the T-cell counterpart of B-CLL either does not exist or is exceedingly rare and thus previously reported cases of T-CLL sharing the chromosomal characteristics of T-PLL may well have been misdiagnosed examples of T-PLL. Isochromosomes 8q are exceptionally found in other types of haematological malignancies. However, i(8q) could not be shown to be the primary lesion in any case in T-PLL and the role of trisomy for 8q, as well of the associated monosomy 8p, is entirely unknown.
Mossafa
H
H
Department of Haematology and Medical Oncology, Hospital Jean Bernard, Poitiers, France.
Brizard
A
A
Huret
J L
JL
Brizard
F
F
Lessard
M
M
Guilhot
F
F
Tanzer
J
J
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000951:Antigens, Neoplasm / Q000032:analysis; D000954:Antigens, Surface / Q000032:analysis; D002869:Chromosome Aberrations; D002898:Chromosomes, Human, Pair 8; D005260:Female; D006801:Humans; D007621:Karyotyping; D015463:Leukemia, Prolymphocytic / Q000235:genetics* / Q000276:immunology; D015458:Leukemia, T-Cell / Q000235:genetics* / Q000276:immunology; D008297:Male; D008875:Middle Aged; D014314:Trisomy
D000951:Antigens, Neoplasm; D000954:Antigens, Surface