Garg Sahil, Dua Amol, Ansari Amir, Tabbara Imad
Department of Internal Medicine, Luminis Health Anne Arundel Medical Center, Annapolis, MD, U.S.A.
Department of Hematology/Oncology, Luminis Health Anne Arundel Medical Center, Annapolis, MD, U.S.A.
Anticancer Res. 2025 Jan;45(1):229-233. doi: 10.21873/anticanres.17409.
BACKGROUND/AIM: Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare and highly aggressive hematologic cancer which is difficult to diagnose and has a lot of overlapping features with other diseases, particularly acute myeloid leukemia (AML). BPDCN shares several immunophenotypic markers with AML, such as CD4, CD56, CD123, and HLA-DR, stating the importance of having extending panel of specific immunohistochemical (IHC) markers.
This report details a case of CLL who presented with worsening symptoms of recurrent infections and leukocytosis. A bone marrow biopsy showed immunoprofile of the blast-like population with CD4-, CD56-, and CD123- positive and CD34- and CD117- negative, based on which BPDCN was diagnosed and patient was started on first-line therapy for BPDCN. However, an extended panel of IHC stains showed positivity for lysozyme, and negativity for TCL1, MPO, and CD303. Thus, BPDCN was excluded according to the WHO 5th edition criteria, and a diagnosis of AML with monocytic differentiation was confirmed.
AML with monocytic differentiation can express CD4, CD56, and CD123, which are very often the only markers considered for diagnosis of BPDCN. An extended panel of IHC analysis is required before making a definitive diagnosis of BPDCN.
背景/目的：母细胞性浆细胞样树突状细胞肿瘤（BPDCN）是一种罕见且侵袭性很强的血液系统癌症，难以诊断，且与其他疾病有许多重叠特征，尤其是急性髓系白血病（AML）。BPDCN与AML有几种免疫表型标志物相同，如CD4、CD56、CD123和HLA - DR，这表明使用扩展的特异性免疫组织化学（IHC）标志物组合的重要性。
本报告详细介绍了一例慢性淋巴细胞白血病（CLL）患者，该患者出现反复感染和白细胞增多症状加重。骨髓活检显示原始样细胞群的免疫表型为CD4、CD56和CD123阳性，CD34和CD117阴性，据此诊断为BPDCN，并开始对患者进行BPDCN一线治疗。然而，扩展的IHC染色组合显示溶菌酶呈阳性，TCL1、MPO和CD303呈阴性。因此，根据世界卫生组织第5版标准排除了BPDCN，并确诊为单核细胞分化的AML。
单核细胞分化的AML可表达CD4、CD56和CD123，这些通常是诊断BPDCN时仅考虑的标志物。在对BPDCN做出明确诊断之前，需要进行扩展的IHC分析。
