Report of Granular Blasts in Adult B-Cell ALL: A Rare Morphological Mimic of AML

Granular ALL is one of the uncommon morphological variants of acute lymphoblastic leukemia (ALL), characterized by cytoplasmic granules in lymphoid blasts. This rare morphological presentation may lead to diagnostic misinterpretation. Case reports of such presentations enhance understanding of disease biology and therapeutic considerations. Case presentation: A 22-year-old woman with Granular ALL has been discussed here. In the Peripheral blood smear (PBS) of this patient, cytoplasmic granules were identified in the cytoplasm of lymphoblasts. Further examinations were conducted on the bone marrow aspiration (BMA) sample of the patient, including karyotyping, flowcytometric and conventional molecular evaluations for ALL. The flow cytometric results were consistent with a diagnosis of B-ALL; the karyotyping analysis showed 47, XX, +17[4], and molecular findings revealed no detectable abnormalities. Conclusion: Due to the misdiagnosis of Granular ALL as AML, the identification of distinguishing diagnostic features of Granular ALL is clinically significant. In this context, flow cytometric, cytogenetic, and molecular findings are invaluable to distinguish between these two types of acute leukemia.