A Rare Case Study of Granular Acute Lymphoblastic Leukemia Combined with Pleural Infiltration.

Background: Acute B-lymphoblastic leukemia (B-ALL) is a common hematologic malignancy characterized by blasts with a variable amount of cytoplasm, typically ranging from minimal to moderate, and containing few cytoplasmic granules. However, granular acute lymphoblastic leukemia, as a rare subtype, is distinguished by the presence of abundant coarse, purplishred granules within the cytoplasm of the blasts, which can be confused with other diseases in clinical diagnosis.

Methods: The patient was examined using bone marrow morphological analysis, flow cytometry, genetic screening, and chromosome karyotype analysis.

Results: The case presented with a high number of coarse, purplishred granules in the cytoplasm of the blasts, which morphologically resembles acute myeloid leukemia and basophilic granulocytic leukemia. Through cytochemical and immunophenotypic analyses, we ultimately diagnosed the case as granular acute lymphoblastic leukemia with pleural infiltration.

Conclusions: Granular acute lymphoblastic leukemia, as a rare subtype, requires particular attention in clinical diagnosis. Cases with similar morphological features should undergo comprehensive diagnostic workups, including cytochemical and immunophenotypic analyses, to avoid misdiagnosis. This case report provides an important reference for further understanding of granular acute lymphoblastic leukemia.