Significance of extra 18q- chromosome in Japanese t(14;18)-positive lymphoma.
Karyotype evolution of t(14;18)-positive lymphoma was studied in 13 Japanese patients. The extra 18q- chromosome, found in six of ten patients with complex karyotypes, was the most common change subsequent to a t(14;18)(q32;q21) chromosome translocation. The additional change was interpreted as being a duplication of an 18q- derived from a t(14;18). The six patients had transformed histology of follicular small cleaved cell lymphoma or diffuse large cell lymphoma, and five of them had extranodal expansion associated with a poor prognosis. These findings indicate that the extra 18q-, together with other chromosome abnormalities, is closely associated with the advanced grade disease of t(14;18)-positive lymphoma, and the extra chromosome is evolutionally comparable with the second Philadelphia (Ph1) chromosome often found in the blastic phase of chronic myelocytic leukemia carrying a t(9;22)(q34;q11). In addition, since the extra 18q- is rarely found in American patients with t(14;18)-positive lymphoma, there appears to be a difference in the karyotype evolution between Japanese and American patients.
Fukuhara
S
S
First Division of Internal Medicine, Faculty of Medicine, Kyoto University, Japan.
Ohno
H
H
Amakawa
R
R
Edamura
S
S
Tomono
N
N
Nasu
K
K
Doi
S
S
Yamabe
H
H
Abe
M
M
Wakasa
H
H
D002869:Chromosome Aberrations / Q000235:genetics*; D002871:Chromosome Banding; D025063:Chromosome Disorders; D002887:Chromosomes, Human, Pair 18; D006801:Humans; D007564:Japan; D008223:Lymphoma / Q000235:genetics*