Granular B lymphoblastic leukemia.

Abstract

A 13-year-old Indian boy presented with extreme lethargy and weakness. On examination, there was no hepatosplenomegaly or lymphadenopathy. His blood count showed a white cell count of 18.8 × 109/L, hemoglobin concentration 107 g/L, and platelet count 70 × 109/L. Examination of a blood film led to suspicion of granular lymphoblastic leukemia. There were 60% blast cells with a moderately high nucleocytoplasmic ratio, delicate chromatin, and 1–3 nucleoli. Many of the blast cells contained prominent azurophilic cytoplasmic granules. There were no Auer rods and granulocyte morphology was normal. The suspected lineage was confirmed by flow cytometric immunophenotyping which showed the blast cells to express CD45 (weak), CD34, CD10, CD19, CD20, cytoplasmic(c) CD79a, CD33, and HLA-DR. There was no expression of myeloperoxidase, cCD3, CD7, CD13, CD64, or CD117. Cytogenetic analysis showed a normal male karyotype. Reverse transcriptase for BCR::ABL1 did not detect p210, p190, or p230 transcripts. Granular acute lymphoblastic leukemia (ALL) is uncommon. Making a distinction from acute myeloid and mixed phenotype, acute leukemia is important and requires myeloperoxidase cytochemistry or immunophenotyping. Most cases are pro-B or common ALL but T-lineage cases have also been reported. In addition to B-lineage-specific markers, there can be aberrant expression of CD131 or CD33.2, 3 There is no specific cytogenetic association and the prognostic significance, if any, is uncertain. The authors declare no conflict of interest