A four year old boy was admitted with a history of abdominal pain and fever for two months maculo popular rash for ten days, and dry cough, dyspnea and wheezing for three days. One examination liver and spleen were enlarged 4 cm and 3 cm respectively below the costal margins. His hemoglobin was 10.0 g/dl, platelet count 37x 109/L and total leukocyte count 70 x 109L, which included 80% eosinophils Bone marrow examination revealed a cellular marrow comprising of 45% blasts and 34% Eosinophils and eosinophilic precursors. The blasts stained negative for myeloperoxidase and non-specific esterase and were positive for CD19, CD10, CD22 and CD20. Which of the following is the most likely diagnosis?
High-Yield Explanation
Answer is C (Acute lymphoblastic leukemia with hypereosinophilic syndrome) The immunophenotypic markers in the question are specific for lymphoid lineage alone and not for myeloid series. Presence of immunophenotypic marker for myeloid lineage is essential before considering a diagnosis of biphenotypic leukemias, or Acute Eosinophilic leukemia (Eosinophils belong to the myeloid series) or Acute myeloid leukemia The patient in question has positive markers for lymphoid series in isolation (CD19,CD10,CD20 and CD22) and hence the single answer by exclusion is Acute Lymphoblastic leukemia (lymphoid series) with hypereosinophilic syndrome.