An Isochromosome 9q: A Rare Event in Pediatric B-ALL.

OBJECTIVES: B-cell acute lymphoblastic leukemia (B-ALL) is one of the most common leukemias affecting the pediatric population. It represents ~25% of cancer diagnoses among children. Specific genetic changes predict the prognosis in B-ALL with recurrent genetic changes. Here we present a case report of a 20-year-old male with B-ALL. The patient presented with acute onset worsening upper extremity pain with pallor, weight loss, dizziness, fatigue, and abnormal complete blood count (CBC). Conventional cytogenetics showed a karyotype of 46,XY,add(9)(q13),i(9)(q10)[19]. DNA FISH analysis performed on the bone marrow showed hemizygous deletion of the 9p21(CDKN2A) in 15.5% of the nuclei examined. The presence of an isochromosome 9q [i(9)(q10) is a rare event in pediatric B-ALL. An isochromosome 9q occurs in 0.6% of the patients studied in the literature. The significance of this abnormality in pediatric B-ALL is not clear. Profiling cases like this to understand the molecular mechanisms of rare chromosomal abnormalities and rare mutations in children with B-ALL could help us to better treat them.

A rare case of B-lymphoid blast phase of chronic myeloid leukemia: Diagnostic challenges.

Chronic myeloid leukemia(CML) is characterized by Philadelphia(Ph) chromosome. About 5% of cases are diagnosed in blast phase. We report a case of a 53-year-old female with no significant medical history, in B-lymphoblast crisis. Flow cytometry demonstrated B-lymphoblasts with no myeloid aberrancies, together with immature neutrophils in blood, and B-lymphoblasts in bone marrow. Cytogenetic studies identified Ph+ with complex abnormalities. Molecular analysis showed positive both for p210 and p190 transcripts in blood. ABL1 mutation analysis by Next Generation Sequencing(NGS) detected Thr315Ile mutation, which confers resistance to many tyrosine kinase inhibitors(TKIs). Eight months later she received allogeneic transplant and is doing well.

A rare case of near-haploid acute lymphoblastic leukemia.

Near-haploid acute lymphoblastic leukemia is seen in <1% of cases and carries an unfavorable prognosis. We report a case in an 18-year old male. He presented with two abnormal clones, one with 27-28 and one with 54-56 chromosomes. Near-haploidy (27-28) carries a poor prognosis and hyperdiploidy (>50) has a good prognosis. The correct diagnosis was critical for this patient's prognosis and treatment. The patient achieved remission after a bone marrow transplant from a 10/10 HLA matched sibling donor. He relapsed six months later and expired seven months later. This case illustrates the need for careful standard and molecular cytogenetic analysis for accurate diagnosis and treatment for this rare type of ALL.

IGH amplification in patients with B cell lymphoma unclassifiable, with features intermediate between diffuse large B cell lymphoma and Burkitt's lymphoma.

B cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma (DLBCL) and Burkitt's lymphoma (BL) (B-UNC/BL/DLBCL) is a new category of tumors that have features resembling both DLBCL and BL. These tumors have large and medium sized cells with greater irregularity of nuclei and more prominent nucleoli than BL. Approximately 35% to 50% have C-MYC rearrangements, although half are non-immunoglobulin variants. We identified six cases of B-UNC/BL/DLBCL with low-level IGH amplification. Four patients died with a median survival of 7 months (range, 6-20). In conclusion, to our knowledge low-level IGH amplification has not been previously described and should be evaluated for in this patient population.