[1350] Adult B Acute Lymphoblastic Leukemia/Lymphoma with C-MYC Rearrangment, a Series of Three Cases

Seble S Chekol, Nahid Nanaji, Ching Chen. University of Maryland Medical Center, Baltimore, MD

Background: Adult B acute lymphoblastic leukemias/lymphoma (B-ALL) are neoplasm of precursor lymphoblast committed to the B-cell lineage with expression of B-cell markers as well as immature markers including CD19, CD10, CD22, PAX5, cytoplasmic CD79a and TdT in most of the cases, while CD20 and CD34 expression is variable. B-cell lineage leukemias with immature phenotype, blastic morphology and C-MYC rearrangement are rare diseases that may pose a diagnostic and management challenge.
Design: The obejective of this study was to to report our experience with 3 such unusual cases of B-lineage leukemias with immature phenotype, blastic morphology and C-MYC rearrangement. The morphologic, immunophenotypic, and cytogenetic features of the leukemic blastic cells of these cases were reviewed in conjunction with clinical and laboratory findings.
Results: The leukemic blastic cells in all the cases are medium to large in size with fine chromatin pattern, scant basophilic cytoplasm and variable amount of cytoplasmic vacuoles and nucleoli. Immunophenotypically, they all lack expression of surface Ig, and have partial heterogeneous CD20 expression (two cases). In one case, the blastic cells are negative for CD20. Two cases have blastic cells with partial TdT expression. The blastic cells in all of the cases are positive for CD45 (dim), CD19, and CD10. Conventional cytogenetic and fluorescent in situ hybridization studies demonstrated chromosomal translocations involving the C-MYC gene in all of the cases. Laboratory findings including LDH and uric acid in two of the cases were markdely elevated. Despite aggresive treatment, two of the patients died within less than a year of their diagnosis (one died only four months after his diagnosis) and the third patient came down with dissminated diease within three months of his diagnosis however was transfered to another insitutuion and was lost to follow up.
Conclusions: Adult B acute Lymphoblastic Leukemia/Lymphoma with C-MYC Rearrangment are unique subtype of B-lymphoblastic leukemia/lymphoma with aggressive clinical behavior and therapeutic response similar to that of Burkitt leukemia/lymphoma. Therefore, early recognition of this entity is crucial for prompt and appropriate therapy and improved clinical outcome.
Category: Hematopathology

Monday, March 4, 2013 9:30 AM

Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 206, Monday Morning


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