Interphase cytogenetics for 1p19q and t(1;19)(q10;p10) may distinguish prognostically relevant subgroups in extraventricular neurocytoma.
Co-deletion of chromosome arms 1p and 19q, characteristic of oligodendroglial tumors, was recently found to be mediated by t(1;19)(q10;p10). To evaluate the prevalence of 1p19q co-deletion and t(1;19) in extraventricular neurocytomas (EVN), we studied tumors from 23 patients, including 13 females and 10 males (median age at diagnosis 34 years, range 2-76 years). Fluorescence in situ hybridization (FISH) studies were performed with probes targeting 1p36/1q25 and 19q13/19p13 to assess for 1p19q co-deletion, as well as chromosome 1 alpha-satellite and 19p12 to detect t(1;19)(q10;p10). FISH was successful in 21 (91%) cases and demonstrated 1p19q co-deletion in five cases (24%) or isolated 1p loss in two cases (10%). Evidence for t(1;19) was found in four (of five) cases with 1p19q co-deletion. Three tumors with 1p19q loss and t(1;19) demonstrated atypical histologic features, compared with one (of 17) tumors without 1p19q co-deletion (P = 0.01, Fisher exact test). In addition, tumors with t(1;19) showed increased mitotic activity compared with tumors without t(1;19) (P = 0.045; Wilcoxon rank sum test). The four patients with t(1;19) developed tumor recurrence (n = 3), or expired (n = 2) 3.5 to 5.5 years after first resection. These results suggest that 1p19q loss and t(1;19) occur in a subset of EVN, and may be associated with aggressive histology in these tumors.
Rodriguez
Fausto J
FJ
Department of Laboratory Medicine, Mayo Clinic, Rochester, MN 55905, USA. rodriguez.fausto@mayo.edu
Mota
Renan A
RA
Scheithauer
Bernd W
BW
Giannini
Caterina
C
Blair
Hilary
H
New
Kent C
KC
Wu
Kevin J
KJ
Dickson
Dennis W
DW
Jenkins
Robert B
RB
D000293:Adolescent; D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000235:genetics* / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D002872:Chromosome Deletion; D002878:Chromosomes, Human, Pair 1 / Q000235:genetics*; D002888:Chromosomes, Human, Pair 19 / Q000235:genetics*; D020732:Cytogenetic Analysis; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D019656:Loss of Heterozygosity; D008297:Male; D008875:Middle Aged; D018306:Neurocytoma / Q000235:genetics* / Q000473:pathology; D009474:Neurons / Q000473:pathology; D011237:Predictive Value of Tests; D013194:Staining and Labeling; D014178:Translocation, Genetic