一例POX阳性的急性B淋巴细胞白血病病例

A Case of POX-Positive B-Cell Acute Lymphoblastic Leukemia

摘要: 临床中急性B淋巴细胞白血病(B-ALL)存在部分非典型病例，细胞形态可与急性单核细胞白血病(AML-M5)相近，同时伴随过氧化物酶(POX)染色阳性、髓系抗原异常表达，极易造成分型误诊。本文报道1例30岁女性患者，入院后完善检验发现骨髓原始细胞占比达78.6%，POX染色阳性率约6%。流式细胞学检测提示细胞表达B淋巴细胞相关标志物，同时伴随髓系抗原CD13、CD33表达；细胞遗传学检查检出特征性染色体易位。结合形态学、免疫学、细胞遗传学及分子生物学(MICM)综合体系，最终确诊为伴髓系抗原表达的急性B淋巴细胞白血病。本病例提示，仅依靠细胞形态与细胞化学染色无法完成精准分型，临床需联合多项检测手段综合判断，提升急性白血病诊断准确率。

Abstract: Atypical cases of B-cell acute lymphoblastic leukemia (B-ALL) occasionally present morphological features similar to acute monocytic leukemia (AML-M5), accompanied by positive myeloperoxidase (POX) staining and aberrant expression of myeloid antigens, which easily lead to misdiagnosis. This paper reports a 30-year-old female patient. Laboratory tests showed that blast cells accounted for 78.6% in bone marrow, and the positive rate of POX staining was about 6%. Flow cytometry confirmed the expression of B-lineage markers along with myeloid antigens CD13 and CD33. Cytogenetic examination detected specific chromosomal translocation. Combined with morphology, immunology, cytogenetics and molecular biology (MICM) classification, the patient was diagnosed as B-ALL with aberrant myeloid antigen expression. This case indicates that accurate classification cannot be achieved merely by cell morphology and cytochemical staining. Multiple auxiliary examinations should be combined for comprehensive evaluation to improve the diagnostic accuracy of acute leukemia.