母细胞性浆细胞样树突状细胞肿瘤(BPDCNs)的自发性缓解(SRs)很少见,记录不佳,和短暂的。我们报告了一名40岁的男性,表现为白细胞减少症和软组织感染。骨髓显示3%的异常细胞。这些细胞的免疫分型显示了抗原CD45+(dim),CD34+,CD117+,CD123+(亮),HLA-DR+(双峰),CD56+(亮),CD33+,CD13+,CD2+,和CD22+(Dim)和CD10+的部分表达,CD36+,和CD7+抗原。所有其他骨髓,单核细胞,淋巴样抗原阴性。遗传研究显示TP53R337C和KRASG12D基因具有复杂的核型和突变。入院时,患者右手和左下肢有皮下结节。流式细胞术多参数(FCM)分析显示存在29%具有先前描述的免疫表型的异常细胞。患者被诊断为BPDCN。患者接受广谱抗生素治疗软组织感染,BPDCN的延迟治疗。没有施用类固醇或化学治疗剂或低甲基化剂。他的血细胞计数改善了皮肤损伤也消失了,直到患者在达到自发缓解5个月后复发。约60%的异常细胞被鉴定。未观察到免疫表型或遗传研究结果的变化。患者接受了6个周期的HyperCVAD化疗方案。通过与HLA无关的供体进行同种异体骨髓移植进行巩固治疗。骨髓移植一年后,病人死于基础疾病的发展,与SARS-CoV-2引起的呼吸道感染相吻合。在现有文献中,SR通常与免疫系统的感染或其他刺激物有关,这表明强大的免疫激活可能在控制白血病克隆中起作用。然而,这种现象的潜在机制尚不清楚。我们假设免疫系统会迫使白血病干细胞(LSC)经历静止状态。这种复制的丧失导致LSC后代死亡,导致BPDCN的SR。
Spontaneous remissions (SRs) in blastic plasmacytoid dendritic cell neoplasms (BPDCNs) are infrequent, poorly documented, and transient. We report a 40-year-old man presenting with bycitopenia and soft tissue infection. The bone marrow exhibited 3% abnormal cells. Immunophenotyping of these cells revealed the antigens CD45+ (dim), CD34+, CD117+, CD123+ (bright), HLA-DR+ (bimodal), CD56+ (bright), CD33+, CD13+, CD2+, and CD22+ (dim) and the partial expression of the CD10+, CD36+, and CD7+ antigens. All other myeloid, monocytic, and lymphoid antigens were negative. Genetic studies showed a complex karyotype and mutations in the TP53R337C and KRASG12D genes. On hospital admission, the patient showed a subcutaneous nodule on the right hand and left lower limb. Flow cytometry multiparameter (FCM) analysis showed the presence of 29% abnormal cells with the previously described immunophenotype. The patient was diagnosed with BPDCN. The patient was treated with broad-spectrum antibiotics for soft tissue infection, which delayed therapy for BPDCN. No steroids or chemotherapeutic or hypomethylating agents were administered. His blood cell counts improved and skin lesions disappeared, until the patient relapsed five months after achieving spontaneous remission. About 60% of abnormal cells were identified. No changes in immunophenotype or the results of genetic studies were observed. The patient underwent a HyperCVAD chemotherapy regimen for six cycles. Consolidation therapy was performed via allogeneic bone marrow transplantation with an HLA-unrelated donor. One year after the bone marrow transplant, the patient died due to the progression of his underlying disease, coinciding with a respiratory infection caused by SARS-CoV-2. In the available literature, SRs are often linked to infections or other stimulators of the immune system, suggesting that powerful immune activation could play a role in controlling the leukemic clone. Nevertheless, the underlying mechanism of this phenomenon is not clearly understood. We hypothesize that the immune system would force the leukemic stem cell (LSC) to undergo a state of quiescence. This loss of replication causes the LSC progeny to die off, resulting in the SR of BPDCN.