Hong L Drum
Genoptix Medical Laboratory, USA
Title: Chronic myelogenous leukemia with B-lymphoid blasts crisis at presentation: A case report and literature review
Biography
Biography: Hong L Drum
Abstract
Chronic myelogenous leukemia (CML) with B-lymphoid blast crisis at presentation is rare. We present a case of a 52-year-old female without a prior known history of hematologic malignancy, who presented with CML with B-lymphoid blast crisis. Review of peripheral blood smears showed moderately increased white blood cells with left-shifted granulocytosis and basophilia. Bone marrow core biopsy demonstrated markedly increased cellularity with marked, left-shifted myeloid hyperplasia. Megakaryocytes were increased with frequent small hypolobated forms. Blasts were increased, comprising 22% of the marrow. The blasts were positive for PAX-5, CD10, CD19, CD34, and TdT, and negative for MPO, consistent with B-lymphoblasts. Quantitative PCR detected BCR-ABL1 transcript (the major breakpoint, p210) at 70.5820% on the International Scale. T(9;22)(q34;q11.2) was detected by cytogenetic study. A diagnosis of CML with B-lymphoid blast crisis at presentation was rendered based on the above findings. Distinguishing a CML with B-lymphoid blast crisis at presentation from a de novo B-acute lymphoblastic leukemia (B-ALL) with t(9;22) often is not easy. The morphologic features that point to a CML with B-lymphoid blast crisis rather than a de novo B-ALL with t(9;22) include concurrent presence of basophilia and left-shifted granulocytosis in the blood, and left-shifted myeloid hyperplasia and increased small atypical megakaryocytes in the bone marrow. Among these morphologic features, the presence of small atypical megakaryocytes/micromegakaryocytes in the bone marrow is considered to be most specific, although not all CML in B-lymphoid blast crises have this morphologic feature.