B-cell acute lymphoblastic leukemia with t(2;9)(p11;p13) involving the immunoglobulin kappa locus (IGK) and PAX-5

S Robert K McCall, Paula Moore, Nancy S,Rosenthal Angela G Niehaus, Bayard Powell, Pettenati Mark J.  

Cytogenetics and Molecular Cytogenetics, Wake Forest University Medical Center, Winston-Salem, North Carolina. pettenat@wakehealth.edu

Previous history

Preleukaemia
-
Malignant disease
-
Inborn condition
-
Main items
-

Clinics case report

Age
30 yrs
Sex
M
Liver
-
Spleen
-
Lymph nodes
+ Tender right axillary, left posterior cervical, and left inguinal lymphadenopathy.
Cns involv
Cytology revealed rare atypical mononuclear cells, favor reactive.

Blood data

Wbc
17.8
Hb
11.3
Platelets
38
Blasts
85
Note
Hypercellular marrow (>90%) with sheets of blasts on bone marrow core biopsy. Bone marrow aspirate smears contained 97% blasts with fine chromatin, single to multiple small nucleoli, and scant pale-blue cytoplasm.

Cyto path

Immunophenotype
Flow cytometric analysis of the peripheral blood identified a population of blasts (80% of all cells) expressing CD45, CD10, CD19, CD20, CD34, HLA-DR, CD33 (variable), CD11b (dim), cCD22, cCD79a, and nTdT. The blasts were negative for CD3, CD4, CD5, CD7, CD56, sIg kappa, sIg lambda, CD13, CD14, CD15, CD36, CD64, and cMPO.
Rearranged ig tcr
Not performed t
Pathology
Acute lymphoblastic leukemia
Electron microscopy
Not performed
Precise diagnosis
B-lymphoblastic leukemia/lymphoma, not otherwise specified

Survival data

Date diagnosis
04-2018
Treatment
ECOG 1910
Complete remission
+
Treatment relat death
-
Relapse
- No relapse in the context of a short follow-up period
Status
A
Date last follow
05-2018
Survival
1

Karyotype

Sample
Bone marrow
Culture time
24
Banding
GTG
Results
45,XY,t(2;9)(p11;p13),-20[18]/46,XY[1]

Other findings

Note
IGK (Immunoglobulin Kappa) (2p11.2). The human IGK locus at 2p12 spans 1820 kb. It consists of 76 IGKV genes belonging to 7 subgroups, 5 IGKJ segments, and a unique IGKC gene.

Images

Atlas Image
Example of chromosome 2;9 translocation. Note: A potential dicentric 9;20 was ruled out with centromeric probes of chromosome 9 and 20. FISH showing fusion (yellow) of IgK (green) [Cyto Cell] and PAX5 (red) [Empire Genomics] on the derived chromosome 9. Note: Negative for BCR/ABL1 fusion by FISH.
Atlas Image
Two interphases demonstrating consistent connection of IgK (green)-PAX5 (red)-IgK (green) suggesting rearrangment/fusion of PAX5/IgK.
Atlas Image
Bone marrow core biopsy showing extensive blast proliferation and peripheral blood (inset) demonstrating atypical blast cytomorphology with occasional deep nuclear fissures.

Comments section

Comments
Note from the Editor: this translocation is a variant of the rare t(9;14)(p13;q32) PAX5/IGH, although the t(9;14) has so far only been described in lymphomas.

Bibliography

Pubmed IDLast YearTitleAuthors
123999652002The utility of spectral karyotyping in the cytogenetic analysis of newly diagnosed pediatric acute lymphoblastic leukemia.Lu XY et al
190205462009Incidence and diversity of PAX5 fusion genes in childhood acute lymphoblastic leukemia.Nebral K et al
261154222015PAX5 alterations in genetically unclassified childhood Precursor B-cell acute lymphoblastic leukaemia.Stasevich I et al

Citation

S Robert K McCall, Paula Moore, Nancy S,Rosenthal Angela G Niehaus, Bayard Powell, Pettenati Mark J.

B-cell acute lymphoblastic leukemia with t(2;9)(p11;p13) involving the immunoglobulin kappa locus (IGK) and PAX-5

Atlas Genet Cytogenet Oncol Haematol. 2019-08-01

Online version: http://atlasgeneticsoncology.org/case-report/208897/b-cell-acute-lymphoblastic-leukemia-with-t(2;9)(p11;p13)-involving-the-immunoglobulin-kappa-locus-(igk)-and-pax-5