Trisomy 5:A Rare Isolated Finding in Pediatric B-lymphoblastic Leukemia

Background and Objectives: In acute leukemia, all diagnostic criteria and treatment protocols are based on cytogenetic and molecular geneticfindings. Despite recent advances in molecular biology, cytogenetic studies still play a pivotal role in the sub-classification of B-lymphoblastic leukemia (B-ALL). B-ALL is characterized by clonal cytogenetic abnormalities with numerical chromosomal aberrations being more common. An extra copy of chromosome 5 is common to see in cases with hyper diploidy. However, a gain of chromosome 5 as a sole anomaly is exceptionally rare in B-ALL. To date, trisomy 5 as a sole abnormality is reported in few cases only. We aimed to report the clinicopathologic profile of this rare finding to increase knowledge and highlight the disease course of these patients.Methods: We report a case of a 14-year boy presented with fever, lethargy and episodes of nasal bleeding for two weeks. He was admitted to the pediatric oncology unit at Indus hospital and health network, Karachi. Flowcytometry performed on peripheral blood using 8-color flowcytometry. Conventional karyotyping was performed by GTG banding. FISH panel was comprisedof dual color dual fusion probes for BCR::ABL1and ETV6::RUNX1whereas break apart probe for KMT2A (Metasystem, Germany).Digital image analysis for karyotyping and FISH was done on Leica Biosystems, Cytovision MB8.Results:Flowcytometry results were consistent with B-ALL. Cytogenetic analysis on his bone marrow aspirate revealed trisomy 5 as a sole abnormality with no evidence of any other clonal cytogenetic abnormality. FISH studies for BCR::ABL1, ETV6::RUNX1and KMT2Ashowed no evidence of gene rearrangements.Conclusion:Trisomy 5 is a very rare cytogenetic aberration. Only few cases reported in children. Inferior outcome is reported in both children and adults. The increasing number of reported cases raises the possibility of a distinct cytogenetic entity. Its prognostic and therapeutic implications are yet to be explored.

Three-way Complex Variant Translocation Involving Long Arm of Chromosome 1 in a Chronic Myeloid Leukemia Patient

Clinical presentation of chronic myeloid leukemia (CML) with classic translocation is similar to those with variant translocations. However, the disease course, outcome and prognosis differsto a large extent. Therefore, it is important to identify and report variant cytogenetic findings. The case is being reported to improve awareness regarding such cases. Case Presentation: Herein we present a case study of 55-year-old male who presented with abdominal pain and fever. The initial complete blood count showed hyperleukocytosis with features suggestive of chronic myeloproliferative leukemia (CML). Bone marrow biopsy and cytogenetic studies were performed for confirmation. Cytogenetic analysis showed presence of complex, three-way (1;9;22)(q12;q34;q11.2) translocation involving chromosomes 1, 9 and 22. The Fluorescencein situhybridization (FISH) studies further confirmed BCR-ABL fusion gene and its atypical pattern was in concordance with aberrations observed in karyotype. The variant translocation we reported herein is unique and rarely reported in literature Discussion:We presented a complex variant case of three-way translocation with characteristic hematological and immunophenotypic findings of CML in chronic phase. To the best of our knowledge, only few cases have been documented so far involving such complex translocation. The initial response to cytoreduction was encouraging while imatinib response has to be followed in present case.Conclusion: It is important to highlight the variant translocations since such findings may influence the disease course hence play a significant role to predict outcome.

Aberrant Expression of CD19 in Early T-cell Precursor Lymphoblastic Leukemia-A Diagnostic Challenge

A systematic approach is required to diagnose acute leukemia. Most of the cases are satisfactorily diagnosed and categorized into subtypes. However, a few cases pose diagnostic dilemma secondary to immunophenotypic aberrancies which are defined as antigens that are normally restricted to a different lineage and expressed by a neoplastic population while absent from its normal non neoplastic counterpart. We report a rare case of Early T-cell PrecursorLymphoblastic Leukemia with aberrant expression of CD19. A 7-year-old boy referred to our hospital with his cervical lymph node biopsy reported as lymphoproliferative disorder. The patient was COVID-19 positive. Chest X-ray showed mild right sided pleuraleffusion with huge mediastinal mass. Flow cytometry on peripheral blood used to establish the diagnosis. The case is reported to improve knowledge regarding aberrant expression of markers. Hematopathology teams should be aware of this phenomenon so that appropriate workup can be done to reach correct diagnosis.