CD4 Antigens ; metabolism ; CD56 Antigen ; metabolism ; Dendritic Cells ; pathology ; Diagnosis, Differential ; Gene Rearrangement, gamma-Chain T-Cell Antigen Receptor ; Hematologic Neoplasms ; drug therapy ; genetics ; metabolism ; pathology ; surgery ; Humans ; Immunohistochemistry ; Leukemia, Myeloid ; pathology ; Lymphoma, Extranodal NK-T-Cell ; pathology ; Precursor B-Cell Lymphoblastic Leukemia-Lymphoma ; pathology ; Precursor T-Cell Lymphoblastic Leukemia-Lymphoma ; pathology ; Skin Neoplasms ; drug therapy ; genetics ; metabolism ; pathology ; surgery

The translocation t(10;11)(p13;q14q21) has been found to be recurrent in acute lymphoblastic and myeloid leukemias, and results in the fusion of the clathrin assembly lymphoid myeloid leukemia (CALM) gene with the AF10 gene; these genes are present on chromosomes 11 and 10, respectively. Because the CALM-AF10 rearrangement is a rare chromosomal abnormality, it is not included in routine molecular tests for acute leukemia. Here, we describe the cases of 2 patients with the CALM-AF10 fusion gene. The first patient (case 1) was diagnosed with T-cell ALL, and the second patient (case 2) was diagnosed with AML. Both patient samples showed expression of the homeobox A gene cluster and the histone methyltransferase hDOT1L, which suggests that they mediate leukemic transformation in CALM-AF10-positive and mixed-lineage leukemia-AF10-positive leukemias. Both patients achieved complete remission after induction chemotherapy. The first patient (case 1) relapsed after double-unit cord blood transplantation; there was no evidence of relapse in the second patient (case 2) after allogenic peripheral blood stem cell transplantation. Since CALM-AF10- positive leukemias have been shown to have poor prognosis with conventional therapy, molecular tests for CALM-AF10 rearrangement would be necessary to detect minimal residual disease during follow-up.
Adolescent ; Adult ; Bone Marrow/pathology ; Chromosomes, Human, Pair 10 ; Chromosomes, Human, Pair 11 ; Cord Blood Stem Cell Transplantation ; Female ; Histone-Lysine N-Methyltransferase/genetics/metabolism ; Homeodomain Proteins/genetics/metabolism ; Humans ; Leukemia, Myeloid, Acute/diagnosis/*genetics/therapy ; Male ; Monomeric Clathrin Assembly Proteins/*genetics ; Oncogene Proteins, Fusion/*genetics ; Precursor T-Cell Lymphoblastic Leukemia-Lymphoma/diagnosis/*genetics/therapy ; Recurrence ; Transcription Factors/*genetics ; Translocation, Genetic

Chromosome 1 band p32 (1p32) aberrations are common in T lymphoblastic leukemia/lymphoma (T-ALL/LBL). Two types of 1p32 aberrations include translocations with different partners and submicroscopic interstitial deletion. Both aberrations are known to result in TAL1 gene deregulation. The t(1;5)(p32;q31) is a rare translocation of 1p32 in T-ALL. We now present the second case of t(1;5)(p32;q31) in T-ALL, which was present as a primary cytogenetic abnormality, with a review of the relevant literature. Interestingly, neither the translocation of the TAL1 gene nor aberrant expression of TAL1 protein was detected by fluorescent in situ hybridization (FISH) and by immunohistochemical staining in this case.
Basic Helix-Loop-Helix Transcription Factors/*genetics/metabolism ; Bone Marrow/pathology ; Chromosomes, Human, Pair 1 ; Chromosomes, Human, Pair 5 ; Humans ; Karyotyping ; Male ; Middle Aged ; Precursor T-Cell Lymphoblastic Leukemia-Lymphoma/*diagnosis/genetics/pathology ; Proto-Oncogene Proteins/*genetics/metabolism ; Tomography, X-Ray Computed ; *Translocation, Genetic