Cytomorphological features of blastic plasmacytoid dendritic cell neoplasm on FNA and cerebrospinal fluid cytology: A review of 6 cases

Cytologic features of blastic plasmacytoid dendritic cell neoplasm involving liver: A case report and literature review

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare but clinically aggressive hematologic malignancy, believed to originate from plasmacytoid dendritic cells (PDCs) although it possesses multilineage potentials. Due to the dismal prognosis, accurate and rapid diagnosis is critical for early management. The disease usually initially involves skin and bone marrow. Here we report the cytopathologic findings in a case of BPDCN involving the liver in a patient previously diagnosed with BPDCN from skin and lymph node biopsies. The fine-needle aspiration specimen from the liver lesion demonstrates a hypercellular smear of atypical epithelioid cells dispersed singly or in loose groups. These cells have enlarged, eccentric, round to irregular nuclei with fine chromatin. The agranular gray-blue cytoplasm shows delicate wispy cytoplasmic extensions and cytoplasmic microvacuoles. Binucleation is common. The concurrent core biopsy shows that the neoplastic plasmacytoid cells with eccentric nuclei were positive for CD4, CD7, CD43, CD56, and CD68, confirming the diagnosis of BPDCN. Mutations of ASXL1 and TET2, classic for BPDCN, and a complex karyotype were detected in skin, bone marrow, and lymph node specimens. We catalog the heterogeneous pathologic features of this rare disease, emphasizing the clinical and histopathological correlation. The differential diagnoses and review of literature are also included. Awareness of this disease and accurate diagnosis are emphasized to aid early management and potentially produce a better clinical outcome.

Dendritic Cell Leukemia: a Review

PURPOSE OF REVIEW

The purpose of this review was to summarize the clinical, diagnostic, and therapeutic features of blastic plasmacytoid dendritic cell neoplasm (BPDCN).

RECENT FINDINGS

Several case reports and series revealed new clinical, molecular, diagnostic, and therapeutic aspects of the disease. The clinical presentation diversity has been confirmed, with frequent leukemic non-cutaneous or rare atypical manifestations. The clonal evolution in the development of BPDCN has not been sufficiently elucidated. Although certain immunophenotypic markers (CD4, TCL1, CD123, CD56, CD303) are indicative of BPDCN, the diagnosis remains in certain cases challenging. Adult (ALL)-type chemotherapy followed by hematopoietic stem cell transplantation (HSCT) is related to a favorable outcome, while chemotherapy alone seems enough in children. Future studies should continue to investigate whether CD123-directed therapies could be utilized. BPDCN is a rare aggressive malignancy that needs an aggressive induction therapy. Although a diagnostic consensus is still lacking, and large retrospective studies are also needed to obtain standardized treatment guidelines, the future perspectives are encouraging, because of novel therapeutic agents that are under investigation.

[Clinical characteristics of 6 patients with blastic plasmacytoid dendritic cell neoplasm]

目的

探讨母细胞性浆细胞样树突细胞肿瘤（BPDCN）的临床特征、治疗和预后。

方法

回顾性分析2008年1月至2016年5月北京协和医院确诊的6例BPDCN患者的临床资料。

结果

6例患者起病时均有皮肤受累，常见表现包括骨髓受累（5例）、淋巴结肿大（4例）、脾大（4例）和肝大（3例）。皮肤外的结外器官受累包括乳腺、上颌窦、椎体和中枢神经系统各1例。肿瘤细胞特征性的免疫表型CD4、CD56、CD123均为阳性。治疗均采用急性淋巴细胞白血病样方案，4例达到完全缓解。中位随访9.5（7~37）个月，中位无进展生存期7个月，中位总生存期9个月。死亡3例，均在诊断后1年内死于原发病复发或进展。

结论

BPDCN侵袭性强，常以皮肤受累为首发症状，骨髓受累、淋巴结和肝脾大较为常见；特征性免疫标志包括CD4、CD56和CD123；目前缺乏有效、标准的治疗方案，预后不良。

A Case of Blastic Plasmacytoid Dendritic Cell Neoplasm Extensively Studied by Flow Cytometry and Immunohistochemistry

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare hematologic malignancy with aggressive clinical course and poor prognosis. Diagnosis is based on detection of CD4⁺ CD56⁺, CD123^high, TCL-1⁺, and blood dendritic cell antigen-2/CD303⁺ blasts, together with the absence of lineage specific antigens on tumour cells. In this report we present a case of BPDCN presenting with extramedullary and bone marrow involvement, extensively studied by flow cytometry and immunohistochemistry, who achieved complete remission after acute lymphoblastic leukemia like chemotherapy and allogeneic hematopoietic stem cell transplantation.