[Preneoplastic and Neoplastic Small Lymphocytic Proliferations Concurrent with Acute Myeloid Leukemia: A Report of...

To report four cases of preneoplastic and neoplastic small lymphocytic proliferations concurrent with acute myeloid leukemia (AML), explore their clinical and laboratory characteristics, and improve the understanding of such diseases.

The bone marrow cell morphology, immunophenotyping, cytogenetics, molecular biological detection and DNA sequencing results of the patients were collected, and the relevant clinical characteristics were analyzed and the literature was reviewed.

Among the 4 patients, there were 2 males and 2 females, with a median age at diagnosis of 64(62-66) years. The median white blood cell count (WBC) was 5.58(2.87-24.4) ×10⁹/L, the median hemoglobin level was 108.5(103-113) g/L, and the median platelet count was 68(17-92)×10⁹/L. The clinical manifestations and bone marrow cell morphological classification of all 4 patients were consistent with AML. Flow cytometry analysis revealed that each of the 4 patients had two distinct abnormal cell populations: group A suggested an early myeloid origin, while group B indicated a mature lymphoid origin, with restricted light chain expression. The results of chromosomal karyotype analysis for the 4 patients were as follows: one patient showed no metaphases due to insufficient cells for analysis; two patients showed no clonal numerical or structural chromosomal abnormalities; one patient had a karyotype of 45,XY,-7［10］/46,XY［10］. The results of fluorescence in situ hybridization showed that case 1 had MLL (KMT2A) gene translocation, case 4 had P53 (17p13.1) deletion, while no abnormalities were detected in the remaining 2 cases. Molecular biological tests revealed that one patient had the MLL∷AF6 fusion gene, one patient showed B-cell gene rearrangement, one patient was detected with biallelic CEBPA mutation, and all 4 patients had gene mutations of varying degrees.

Preneoplastic and neoplastic small lymphocytic proliferations are classified as indolent lymphoproliferative disorders. When accompanied by AML, their clinical features are often overlooked. Flow cytometry can effectively identify the nature of CLL/MBL obscured by myeloid lesions through the simultaneous detection of dual-lineage markers. The treatment should adopt combined regimens that take into account both lymphoid and myeloid lesions, and early hematopoietic stem cell transplantation (HSCT) after disease remission may serve as a key strategy for improving prognosis.