Thiotepa-busulfan-fludarabine-based conditioning as a promising approach prior to allogeneic hematopoietic stem cell transplantation in patients with blastic plasmacytoid dendritic cell neoplasm

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare and aggressive myeloid malignancy associated with a poor prognosis. Although allogeneic hematopoietic stem cell transplantation (allo-HSCT) has emerged as a potential treatment strategy for BPDCN, standardized conditioning regimens remain lacking. In this manuscript, we present two cases of BPDCN that were treated with a thiotepa-busulfan-fludarabine (TBF)-based conditioning regimen prior to allo-HSCT. Both cases demonstrated complete remission post-transplantation, sustained donor chimerism, and remission maintenance, suggesting the potential efficacy of the TBF conditioning regimen for BPDCN transplantation. Given the small sample size in our study, we emphasize caution and advocate for larger studies to confirm the efficacy of TBF in the treatment of BPDCN.

Low-dose venetoclax combined with azacitidine for blastic plasmacytoid dendritic cell neoplasm: a case report and literature review

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare hematologic malignancy that is highly aggressive with a poor prognosis. There is no standard treatment for BPDCN. Although conventional chemotherapies are usually sensitive in the initial therapy, relapse and drug resistance are inevitable within a short duration. Targeted therapies have enlightened new prospects for the treatment of BPDCN, especially for those in a frail state and intolerable to standard chemotherapies or hematopoietic stem cell transplantation. Here, we report an 82-year-old man diagnosed with cutaneous-limited BPDCN. Considering the old age and limited involvement of the tumor, we reduced the dosage of venetoclax. His skin lesions subsided significantly after 1 cycle of azacytidine (100 mg d1-7) combined with reduced doses of venetoclax (200 mg d1-14). The reduction in the dose of venetoclax avoided severe myelosuppression while achieving satisfactory outcomes. The patient received 2 cycles of therapy with no skin lesions re-occurred for 7 months before relapsing.

Treatment of patients with blastic plasmacytoid dendritic cell neoplasm (BPDCN): focus on the use of tagraxofusp and clinical considerations

BPDCN is an aggressive myeloid malignancy with a poor prognosis. It derives from the precursors of plasmacytoid dendritic cells and is characterized by CD123 overexpression, which is seen in all patients with BPDCN. The CD123-directed therapy tagraxofusp is the only approved treatment for BPDCN; it was approved in the US as monotherapy for the treatment of patients aged ≥2 years with treatment-naive or relapsed/refractory BPDCN. Herein, we review the available data supporting the utility of tagraxofusp in treating patients with BPDCN. In addition, we present best practices and real-world insights from clinicians in academic and community settings in the US on how they use tagraxofusp to treat BPDCN. Several case studies illustrate the efficacy of tagraxofusp and discuss its safety profile, as well as the prevention, mitigation, and management of anticipated adverse events.

Ulcerating skin lesions from blastic plasmacytoid dendritic cell neoplasm responding to low-dose radiotherapy-a case report and literature review

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare hematologic malignancy that can manifest with skin nodules and erythematous plaques. In most cases BPDCN progresses rapidly, causing multiple skin lesions and also affecting internal organs and bone marrow, warranting initiation of systemic therapies or hematopoietic stem cell transplantation (HCT). Although not curative, radiotherapy for isolated lesions might be indicated in case of (imminent) ulceration and large or symptomatic lesions. To this end, doses of 27.0-51.0 Gy have been reported. Here, we present the case of an 80-year-old male with BPDCN with multiple large, nodular, and ulcerating lesions of the thorax, abdomen, and face. Low-dose radiotherapy of 2 × 4.0 Gy was administered to several lesions, which resolved completely within 1 week with only light residual hyperpigmentation of the skin in affected areas and reliably prevented further ulceration. Radiotoxicity was not reported. Therefore, low-dose radiotherapy can be an effective and low-key treatment in selected cases of BPDCN, especially in a palliative setting, with a favorable toxicity profile.

Azacitidine maintenance therapy for blastic plasmacytoid dendritic cell neoplasm allograft: A case report

BACKGROUND

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare, highly invasive malignant neoplasm. There is no universally accepted standard of care because of its rarity and the dearth of prospective research. It is still challenging for some patients to achieve persistent clinical remission or cure, despite the success of allogeneic hematopoietic stem cell transplantation (allo-HSCT), indicating that there is still a significant recurrence rate. We report a case of prevention of BPDCN allograft recurrence by azacitidine maintenance therapy and review the relevant literature.

CASE SUMMARY

We report a 41-year-old man with BPDCN who was admitted to hospital due to skin sclerosis for > 5 mo' duration. BPDCN was diagnosed by combined clinical assessment and laboratory examinations. Following diagnosis, the patients underwent induction consolidation chemotherapy to achieve the first complete remission, followed by bridging allo-HSCT. Post-transplantation, azacitidine (75 mg/m2 for 7 d) was administered as maintenance therapy, with repeat administration every 4-6 wk and appropriate extension of the chemotherapy cycle. After 10 cycles, the patient has been disease free for 26 mo after transplantation. Regular assessments of bone marrow morphology, minimal residual disease, full donor chimerism, Epstein-Barr virus, and cytomegalovirus all yielded normal results with no abnormalities detected.

CONCLUSION

Azacitidine may be a safe and effective maintenance treatment for BPDCN following transplantation because there were no overt adverse events during the course of treatment.

[Clinicopathological diagnosis of blastic plasmacytoid dendritic cell neoplasm: Report of three cases]

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare disease with a poor prognosis. It frequently affects the skin; indeed, dermal lesions may be the first clinical manifestation. We report three cases of BPDCN where the patients presented with skin lesions and describe the clinical, histopathological and immunohistochemical findings, its molecular characteristics and metastatic work-up. One of the patients remains in a clinical trial with IMGN632, a molecule directed against CD123, while the other two patients died after different therapeutic regimens. BPDCN is a complex diagnostic challenge which, together with its poor prognosis, requires close clinical-pathological cooperation in order to accelerate its diagnosis and offer early therapeutic alternatives with drugs directed against specific molecular targets.

Venetoclax monotherapy as front-line therapy for blastic plasmacytoid dendritic cell neoplasm

Venetoclax is an approved treatment for relapsed/refractory Blastic Plasmacytoid Dendritic Cell Neoplasm (BPDCN). We report a unique case of venetoclax monotherapy used for front-line induction and as a bridge to allogeneic hematopoietic stem cell transplantation (HCT). Venetoclax therapy resulted in rapid complete resolution of skin lesions, however, treatment interruption due to neutropenia led to brisk cancer recurrence. Fortunately, the patient responded to re-challenge and was able to undergo HCT. Venetoclax is active in the first-line treatment setting for BPDCN, however its effect on blood counts and durability of response should be further studied.

Expanding the Immunophenotypic Spectrum of Neoplastic and Reactive Plasmacytoid Dendritic Cells

OBJECTIVES

Targeted therapies for blastic plasmacytoid dendritic cell neoplasm (BPDCN) have presented a diagnostic dilemma for differentiating residual BPDCN from reactive plasmacytoid dendritic cells (pDCs) because these conditions have a similar immunoprofile, necessitating discovery of additional diagnostic markers.

METHODS

Fifty cases of BPDCN involving bone marrow (26/50) and skin (24/50) as well as other hematologic malignancies (67) and nonneoplastic samples (37) were included. Slides were stained using a double-staining protocol for the following immunohistochemical marker combinations: TCF4/CD123, TCF4/CD56, SOX4/CD123, and IRF8/CD123.

RESULTS

The nuclear marker SOX4 is expressed in neoplastic pDCs; in our cohort, SOX4/CD123 showed 100% sensitivity and 98% specificity in distinguishing BPDCN from reactive pDCs and other neoplasms. TCF4/CD56 had a 96% sensitivity and 100% specificity for BPDCN. IRF8 is a nonspecific marker that is positive in BPDCN and pDCs as well as other myeloid malignancies.

CONCLUSIONS

The novel immunohistochemical combination SOX4/CD123 distinguishes BPDCN, including CD56-negative BPDCN, from both reactive pDCs and other neoplasms. Because of their high diagnostic sensitivity and specificity, the double-staining marker combinations TCF4/CD123, TCF4/CD56, and SOX4/CD123 can be used to confirm lineage in BPDCN cases and detect minimal/measurable residual disease in tissue specimens.

Plasmacytoid dendritic cell neoplasms

Plasmacytoid dendritic cells (pDCs) are type I interferon-producing cells that modulate immune responses. There are two types of pDC neoplasms: 1) mature pDC proliferation (MPDCP) associated with myeloid neoplasm and 2) blastic pDC neoplasm (BPDCN). MPDCP is a clonal expansion of mature pDCs that is predominantly associated with chronic myelomonocytic leukemia. In contrast, BPDCN is a clinically aggressive myeloid malignancy involving the skin, bone marrow, lymphatic organs, and central nervous system. There are various types of skin lesions, ranging from solitary brown or violaceous to disseminated cutaneous lesions, which often spread throughout the body. The expression of CD4, CD56, CD123, and pDC markers (TCL-1, TCF4, CD303, and CD304, etc.) are typical immunophenotype of BPDCN. Historically, BPDCN treatment has been based on acute leukemia regimens and allogeneic hematopoietic cell transplantation in selected patients. Recent advances in molecular biology and genetics have led to the development of targeted agents, such as tagraxofusp (a recombinant fusion protein targeting CD123), anti-CD123 CAR-T cells, XmAb14045, and IMGN632. Lastly, this review provides a comprehensive overview of pDC neoplasms.

[Blastic plasmacytoid dendritic cell neoplasm: A clinico-pathological retrospective analysis of thirteen cases]

OBJECTIVE

To investigate the clinicopathological features of blastic plasmacytoid dendritic cell neoplasm (BPDCN).

METHODS

A total of 13 cases of BPDCN diagnosed in Peking University First Hospital from January 2013 to March 2022 were collected. The clinical features, histopathological characteristics, immunophenotypes and prognosis of the patients were analyzed retrospectively, and the related literatures was reviewed as well.

RESULTS

Among the 13 patients, 11 were male and 2 were female, with a median age of 62 years (ranging from 5 to 78 years). Among them, single organ involvement occurred in 5 cases, all of which presented with skin lesions. Two or more organs were involved in other 8 cases (single organ with bone marrow involved in 3 cases; skin, bone marrow and lymph node involved simultaneously in 3 cases; skin, bone marrow, lymph node and spleen involved simultaneously in 2 cases). Histopathologically, it was characterized by the proliferation of medium to large atypical blastic cells, which infiltrated the whole thickness of dermis. When involved, the bone marrow lesions mainly appeared in a diffuse pattern, while the lymph node structure was usually destroyed, and the red pulp of the affected spleen was diffusely invaded. Immunohistochemical staining showed that all the 13 cases were positive for CD4, CD56, and CD123 (13/13) in varying degrees. All the 9 cases expressed TCL1 (9/9). Variable expression of CD68 (KP1) (8/13), TdT (7/12), CD117 (2/6), and high Ki-67 proliferation index (40%~80%) were showed. The neoplastic cells lacked expressions of CD20, CD3, MPO, CD34, or CD30; EBER in situ hybridization were negative (0/9). After definite diagnosis, 6 cases received chemotherapy, among which 1 received adjuvant radiotherapy, and 2 received subsequent bone marrow transplantation. Another 2 cases only received maintenance treatment. The median follow-up time was 14 months (ranging from 6 to 36 months), 5 patients died of the disease (6 to 18 months), 3 patients survived (7 to 36 months up to now), and the remaining 5 patients lost follow-up.

CONCLUSION

BPDCN is a rare type of malignant lymphohematopoietic tumor with aggressive behavior and poor prognosis. The diagnosis should be made combining clinical features, histopathology, and immunohistochemical phenotype. Attention should be paid to differentiating BPDCN from other neoplasms with blastoid morphology or CD4+CD56+ tumors.

Incidence, prognostic factors and survival outcomes in patients with blastic plasmacytoid dendritic cell neoplasm: a retrospective study in the SEER database

There are few large-scale epidemiological and prognostic studies on blastic plasmacytoid dendritic cell neoplasm (BPDCN) due to its rarity. We used the Surveillance, Epidemiology, and End Results (SEER) database to investigate the incidence, clinical characteristics, prognostic factors, and survival trends of BPDCN. The age-adjusted incidence of BPDCN had a bimodal pattern with peaks in those under 20 and above 60 years. Of 697 patients, the median age at diagnosis was 31 years. The most common primary sites were lymph nodes (59.4%), followed by bone marrow (17.1%) and skin (11.6%). Extranodal involvement (59.7%) was more common in patients aged 60 years and above, while lymph node involvement was predominant in other age groups. The 1-year, 3-year, and 5-year OS rates were 90.7%, 83.7%, and 82.3% in patients aged under 20, but dropped to 53.1%, 27.7%, and 20.0% in patients aged 60 and above. Multivariate Cox regression analysis revealed that age, sex, and first malignancy were independent prognostic factors for OS. Based on this regression model, a nomogram was built with high discrimination and calibration. The incidence, clinical characteristics, and prognosis of BPDCN patients vary by age group. Moreover, using the nomogram to predict OS can help guide individualized evaluations and clinical decisions.

Top Ten Lymphoproliferative Lesions Not to Miss When Evaluating Oral Ulcer Biopsies

BACKGROUND

Oral ulcers represent a full thickness loss of the mucosal epithelium leading to exposure of the submucosal connective tissue. These are common and usually self-limited lesions, although they may sometimes result from neoplasms, most commonly squamous cell carcinoma. Lymphoproliferative disorders may be difficult to diagnose in apthous ulcers since they mimic reactive inflammation.

METHODS

This review presents ten rare oral lymphoid proliferations which should not be missed when assessing oral ulcer biopsies.

RESULTS

The ten lesions include several with diagnostic cells which look similar to the histiocytes of a reactive inflammatory ulcer, including Rosai-Dorfman disease, reticulohistiocytoma, Langerhans cell histiocytosis, and traumatic ulcerative granuloma. Other lesions, such as EBV-positive mucocutaneous ulcer, extranodal marginal zone lymphoma of mucosal-associated lymphoid tissue, and plasmablastic lymphoma have lymphoid and/or plasma cell differentiation that mimic the reactive lymphocytes and plasma cells found in reactive ulcers. Two dendritic cell lesions, follicular dendritic cell sarcoma and blastic plasmacytoid dendritic cell neoplasm, both have distinct phenotypes which are required to make an accurate diagnosis.

CONCLUSION

Each of these lesions are diagnosed by evaluating their histology, along with their phenotypic profile, which is sometimes enhanced by pertinent molecular findings.

Systemic mastocytosis mimicking blastic plasmacytoid dendritic cell neoplasm: a case report

BACKGROUND

Systemic mastocytosis (SM), a rare myeloid neoplasm, is defined as a clonal and neoplastic proliferation of mast cells in at least one extracutaneous organ(s). The pathologic diagnosis and treatment of SM are challenging.

CASE PRESENTATION

We presented a 44-year-old male patient who had endured abdomen discomfort for 4 years and diarrhea for 5 months. Colonoscopy and PET/CT found a protuberant lesion in the cecum with adjacent lymphadenopathy. Histopathology of the cecum biopsy showed diffuse infiltration of medium-sized round/oval cells in lamina propria with immunohistochemical expressions of CD45, CD117, CD25, CD68, CD123, CD56, CD4, and CD35, mimicking blastic plasmacytoid dendritic cell neoplasm. Sanger sequencing revealed missense mutation (D816V) in the exon 17 of KIT gene. Serum tryptase level was 38.56 ng/ml. No abnormality was found in skin examination and bone marrow biopsy. No primitive cells were observed in bone marrow smear and peripheral blood smear. The diagnosis of aggressive SM with intestinal tract involvement was established. The patient received avapritinib treatment at an initial dosage of 200 mg once daily and exhibited dramatic clinical improvement but memory impairment within 1 month. No recurrence was observed in 1-year follow-up at the adjusted avapritinib dose (75 mg once daily).

CONCLUSIONS

SM is very rare and should be considered in patients with long-term diarrhea symptoms and hematopoietic/lymphoid-appearing tumors. KIT D816V mutation contributes to the differentiation of CD123, CD4, and CD56 immunoreactive SM from blastic plasmacytoid dendritic cell neoplasm. The rare side-effect of memory impairment in this case helps to accumulate the experience of avapritinib in treating KIT D816V-mutant SM.

Relapse of tagraxofusp treated blastic plasmacytoid dendritic cell neoplasm with loss of CD123 expression

Tagraxofusp, a CD123-based-targeted immunotherapy, was recently approved to treat blastic plasmacytoid dendritic cell neoplasm (BPDCN) with excellent response. Also, a subset of BPDCN shows resistance to tagraxofusp. These resistant cases continue to express CD123, which forms the basis of the continued utility of tagraxofusp in newer combination chemotherapies to overcome resistance in BPDCN. Herein, we report a case of an elderly male with BPDCN that achieved complete remission on initial primary treatment with tagraxofusp. However, BPDCN relapsed after 1.5 years while on treatment, with loss of CD123 expression. At relapse, the neoplasm was comprehensively immunophenotyped by flow cytometry (performed on both peripheral blood and bone marrow specimen) and by immunohistochemical evaluation of the bone marrow clot section. The neoplasm at relapse was diagnostic of BPDCN with a lack of CD123 expression. This case highlights a potential limitation of current and upcoming tagraxofusp-based multidrug therapies, at least in a subset of refractory BPDCN. We believe our report will serve as a sentinel to incite future investigations involving alternate resistance mechanisms in BDPCN.

Blastic plasmacytoid dendritic cell neoplasm with skin and bone marrow involvement: Report of three cases

BACKGROUND

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare and highly aggressive hematopoietic malignancy. BPDCN is difficult to diagnose because of the overlap in morphologic and immunophenotypic features with various cutaneous lymphatic hematopoietic tumors.

CASE SUMMARY

We report on three BPDCN cases, all characterized by skin nodules and examined by histology, immunohistochemical detection, in situ hybridization for Epstein-Barr virus, and follow-up. We also review the relevant literature. All patients were positive for CD56 and negative for Epstein-Barr encoded small RNA. Two patients had bone marrow involvement. Chemotherapy is the main treatment for BPDCN, but case 1 showed bone marrow suppression and case 2 developed recurrence after chemotherapy. Case 1 survived for 7 mo, case 2 for 17 mo, and case 3 for 9 mo.

CONCLUSION

An accurate pathological diagnosis is a precondition for treatment, and the diagnosis of BPDCN should be based on a combination of clinical symptoms, pathological characteristics, immunophenotype, and other auxiliary examinations. It is necessary to clarify the clinicopathological features and biological behavior of BPDCN to improve its understanding by both clinicians and pathologists. Case 2 survived significantly longer than the other two cases, suggesting that the treatment received by case 2 was more effective.

Rapidly progressing blastic plasmacytoid dendritic cell neoplasm causing diffuse skin thickening: A case report with sequential computed tomography examinations

Blastic plasmacytoid dendritic cell neoplasm is a rare aggressive myeloid malignancy thought to be derived from precursor plasmacytoid dendritic cells. Rapid progression and poor prognosis have been known. We herein present a case of BPDCN in a previously healthy man who presented with suddenly developed multiple deep purple skin rashes, with sequential computed tomography examinations. The follow-up computed tomography demonstrated that multiple skin nodules observed in the initial MRI fused, resulting in a thickening of the entire skin, with some surface erosions and crusting. Blastic plasmacytoid dendritic cell neoplasm should be considered in the differentials in patients with a sudden onset and rapidly progressing skin rash or thickening.

Venetoclax in relapsed/refractory blastic plasmacytoid dendritic cell neoplasm with central nervous system involvement: a case report and review of the literature

BACKGROUND

We describe a patient with blastic plasmacytoid dendritic cell neoplasm with central nervous system involvement and the outcome of venetoclax use in this setting.

CASE PRESENTATION

A 54-year-old Caucasian male was referred to the Haematology Unit with an enlarged inguinal lymph node which was diagnostic of a blastic plasmacytoid dendritic cell neoplasm. The staging revealed disseminated disease (skin, visceral, lymph nodes, and bone marrow). He received chemotherapy with an acute myeloid leukaemia-like regime. Afterwards, he underwent allogeneic haematopoietic stem cell transplantation, though it was not successful, showing a relapse 14 months later with hepatic and central nervous system dissemination. Intrathecal chemotherapy was administered, and venetoclax (anti-bcl2 agent) was started in an off-label indication based on most recent literature. The disease halted its course for 3 months. In the end, the patient's disease progressed and so he succumbed due to infectious complications.

CONCLUSIONS

Venetoclax monotherapy seems not enough to control the disease progression under CNS involvement and other treatments should be investigated.

A misdiagnosed case of blastic plasmacytoid dendritic cell neoplasm experiencing multiple recurrences who underwent allogeneic stem cell transplantation: a case report

BACKGROUND

Blastic plasmacytoid dendritic cell neoplasm represents a rare type of hematologic malignancy that often manifests itself through various skin lesions. It commonly affects the elderly male population. Lymph nodes, peripheral blood, and bone marrow involvement are the typical findings that justify its aggressive nature and dismal prognosis. On histopathological assessment, malignant cells share some similarities with blastic cells from the myeloid lineage that make immunohistochemistry staining mandatory for blastic plasmacytoid dendritic cell neoplasm diagnosis.

CASE PRESENTATION

A 35-year-old Asian man presented with cervical lymphadenopathy followed by an erythematous lesion on his left upper back. At first, the lesion was misdiagnosed as an infectious disease and made the patient receive two ineffective courses of azithromycin and clarithromycin. Six months later, besides persistent skin manifestations, he felt a cervical mass, which was misdiagnosed as follicular center cell lymphoma. Tumor recurrence following the chemoradiation questioned the diagnosis, and further pathologic assessments confirmed blastic plasmacytoid dendritic cell neoplasm. The second recurrence occurred 3 months after chemotherapy. Eventually, he received a bone marrow transplant after complete remission. However, the patient expired 3 months after transplant owing to the third recurrence and gastrointestinal graft versus host disease complications.

CONCLUSIONS

Early clinical suspicion and true pathologic diagnosis play a crucial role in patients' prognosis. Moreover, allogenic bone marrow transplant should be performed with more caution in aggressive forms of blastic plasmacytoid dendritic cell neoplasm because of transplant side effects and high risk of cancer recurrence.

Blastic plasmacytoid dendritic cell neoplasm with genetic mutations in multiple epigenetic modifiers: a case report

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare, aggressive hematodermic malignancy derived from plasmacytoid dendritic cell precursors. Despite advances in our understanding of tumor cell surface markers, the pathogenesis of BPDCN remains largely unknown. No standard or optimal treatments are available for BPDCN, and the prognosis is usually poor. We report herein a case of BPDCN that harbored multiple genetic mutations in epigenetic modifiers such as TET2 and ZRSR2. Genetic studies in patients with BPDCN may provide insights into the underlying pathogenesis, prediction of clinical prognosis, and development of better targeted therapeutics for this rare clinical entity.

Pediatric blastic plasmacytoid dendritic cell neoplasm: report of four cases and review of literature

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare and aggressive hematological malignancy with poor outcome. Four children with BPDCN treated at our hospital were enrolled. All the four cases presented with cutaneous lesions. Bone marrow and central nervous system was involved in 50% and 25% of patients, respectively. The whole exome sequencing analysis revealed that KMT2 family genes were the most frequently mutated (4/4, 100%), followed by IKZF2 (2/4, 50%). The point mutation p.D348N was found in three patients and one patient had p.C394Y mutation in the KMT2C gene. Translocation of KMT2A-MLLT3 was found in Case 2. Case 1 had complex karyotype, who was induced by acute myeloid leukemia-like regimens. Although he received allogeneic hematopoietic stem cell transplantation twice as well as CD123 chimeric antigen receptor T cell therapy, the disease still progressed and he died 37 months after diagnosis. The other three patients were treated with Interfant-99 protocol. They tolerated the therapy well without significant toxicities and now in complete remission so far with a median follow up time of 9 months. More studies are needed to address the question whether the complex karyotype and KMT2 family genes are the causes of the relapse and refractory in BPDCN.

Tagraxofusp followed by combined azacitidine and venetoclax in blastic plasmacytoid dendritic cell neoplasm: A case report and literature review

INTRODUCTION

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare and aggressive hematologic malignancy that originates from plasmacytoid dendritic cells. It can involve skin, bone marrow, and/or lymph nodes. There is no consensus recommendation regarding treatment especially in the relapsed setting. Tagraxofusp, a CD123 directed agent, was recently approved by the Food and Drug Administration to treat BPDCN. We report a case of an elderly patient with diagnosis of BPDCN who was treated initially with tagraxofusp followed by azacitidine and venetoclax combination on relapse.

CASE REPORT

A 79 year old male presented with violaceous skin lesions. He had no other symptoms. Biopsy of these lesions was consistent with a diagnosis of BPDCN. Further testing showed no extracutaneous involvement.Management and outcome: Tagraxofusp was started at full dose (12 mcg/kg). This dose was not tolerated well. Patient could only tolerate the lowest dose (5 mcg/kg). Toxicities included elevated liver function tests, hyperglycemia, capillary leak syndrome, and pancreatitis. Dose escalation on progression was not possible due to side effects. Treatment was switched to venetoclax and azacitidine. Combination treatment was tolerated very well and patient showed major cutaneous response after 5 cycles and continues to do well.

DISCUSSION

Tagraxofusp is a novel therapy that needs more real-world experience. This case describes the clinical course of an elderly patient on tagraxofusp. We also review the literature of azacytidine/venetoclax combination as a potential yet tolerable treatment option for this rare disease entity. This is the fourth case in literature to be treated with this combination.

Blastic Plasmacytoid Dendritic Cell Neoplasm: Single Center Experience on a Rare Hematological Malignancy

Purpose

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare and poor prognostic hematological malignancy. There is still no standard treatment established for BPDCN patients. We aim to summarize the main clinical, biological features and treatment of 9 BPDCN patients.

Methods

Nine patients with BPDCN who had been diagnosed between July 2008 and December 2018 in Ankara University School of Medicine, were retrospectively evaluated.

Results

All patients (n = 9) were male, median age was 64 (21-80). Five patients (55.6%) had bone marrow infiltration, 5 patients (55.6%) cutaneous lesions, 6 patients (66.7%) lymph node involvement, 2 patients (22.2%) central nervous system involvement and 2 patients (22.2%) spleen involvement at time of diagnosis. Complex karyotype was observed in 2 patients. CHOP was given to 5 patients (55.6%), hyper-CVAD to 2 patients (22.2%), fludarabine, cyclophosphamide and mitoxantrone to 1 patient (11.1%) and cyclophosphamide, etoposide, methylprednisolone to 1 patient (11.1%) as first line chemotherapy. Four patients (44.4%) underwent allogeneic hematopoietic stem cell transplantation (AHSCT) in complete remission (CR) 1. Venetoclax was given to a transplant ineligible patient who had skin and lymph node involvement, with the off-label use. The median follow-up time was 15.9 months (3-48.6 months). Estimated median overall survival was 15.9 + 1.6 (95% CI 12.7-19.1) months.

Conclusion

Intensive induction therapies followed by AHSCT in CR seems to be best approaches for patients with BPDCN. Thus, more effective treatment strategies particularly targeted therapies should be warranted to improve the survival of patients with this rare disease.

Tagraxofusp as treatment for patients with blastic plasmacytoid dendritic cell neoplasm

INTRODUCTION

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare, aggressive hematologic malignancy that previously lacked standardized therapeutic approaches. CD123 (interleukin-3 receptor alpha unit) is highly expressed in many hematologic malignancies, including BPDCN. Tagraxofusp-ezrs (tagraxofusp from herein) is an agent that consists of interleukin-3 fused to a truncated diphtheria toxin, targeting CD123. The Food and Drug Administration recently approved tagraxofusp as therapy for BPDCN for adults and children aged 2 years and older.

AREAS COVERED

We discuss the history and clinical background of BPDCN along with tagraxofusp as its first-line therapy. We review the clinical efficacy and safety profile of tagraxofusp in adults including proposed sensitivity and resistance. Finally, we summarize tagraxofusp use in the pediatric population.

EXPERT OPINION

Tagraxofusp is a newly approved therapy for BPDCN, a hematologic malignancy that has overall historically poor outcomes. With its significant efficacy, many patients were successfully bridged to stem cell transplantation in the clinical trial leading to its ultimate approval. Clinical awareness for major toxicities, including capillary leak syndrome will be a critical aspect of using this novel agent. In the future, investigation of its use in other hematologic malignancies and expansion of clinical trials in pediatric populations with BPDCN are warranted.

Blastic Plasmacytoid Dendritic Cell Neoplasm: Case Report and Literature Overview

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a malignancy with high frequency of skin involvement. A 39-year-old Caucasian female was suffering from weakness, myalgia, and skin eruption, which appeared during treatment of chlamydiosis with antibiotics in July 2016. Based on clinical presentation, laboratory investigations, and histological examination of skin and bone marrow biopsy, a diagnosis of BPDCN with the involvement of skin, bone marrow, and central nervous system was made. The patient was put on acute lymphoblastic leukemia-like chemotherapy and achieved complete remission in November 2016, the eruption regressed. In January 2017, allogeneic bone marrow transplantation from matched sibling was performed. Since May 2017, the cutaneous relapse with loss of CD56 expression has developed. This clinical case demonstrates the importance of laboratory tests. Histological examination helps to clarify a diagnosis of cutaneous lymphoma; however, a specific type of lymphoma needs immunohistochemical analysis. In our case, BPDCN at the initial stage presented like a systemic vasculitis.

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.

Blastic plasmacytoid dendritic cell neoplasm with a history of cytopenia: A case report

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare and aggressive hematologic malignancy arising from plasmacytoid dendritic cell precursors. The disease typically manifests in the skin, but it also evolves into a leukemic phase or can be complicated by other myeloid malignancies, especially myelomonocytic tumors. The association between these neoplasms is not fully elucidated. We report a case of BPDCN with a history of cytopenia that was supposed to be chronic myelomonocytic leukemia. The patient received intensive chemotherapy and achieved complete remission, but soon relapsed. The successive occurrence of myelomonocytic neoplasm and BPDCN is in accordance with the fact that they evolve from a common cell origin with a multilineage potential for myelomonocytic and plasmacytoid dendritic cell differentiation. This case may shed further light on the mystery of biology and the histogenesis of BPDCN.

Blastic Plasmacytoid Dendritic Cell Neoplasm: The Dermatologist's Perspective

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare, aggressive malignancy derived from the plasmacytoid dendritic cell that commonly involves the skin. Cutaneous involvement is often the initial presentation, with deep purple or red-brown macules, plaques, or tumors. As such, dermatologists may be the first to see these patients and, in addition to oncologists, should be familiar with its presentation to facilitate early diagnosis, helping to distinguish it from acute myelogenous leukemia cutis.

Hematopoietic Cell Transplant for Blastic Plasmacytoid Dendritic Cell Neoplasm

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare aggressive hematologic malignancy derived from precursors of plasmacytoid dendritic cells. Historically, BPDCN has had few available treatment options and a poor prognosis. The emergence of novel targeted therapies, namely tagraxofusp, has changed the treatment landscape of BPDCN, but data are lacking regarding the long-term durability of responses. Despite absence of randomized data, allogeneic hematopoietic cell transplant has become the de facto option for patients with BPDCN who achieve a first complete remission. As new therapies continue to emerge, it will be important to evaluate the role of postallograft maintenance/consolidation.

New perspectives in genetics and targeted therapy for blastic plasmacytoid dendritic cell neoplasm

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is one rare but clinically aggressive hematological malignancy, and it is typically characterized by skin lesion and bone marrow involvement. Diagnosis of BPDCN relies on the immunophenotype positive for four of CD4, CD56, CD123, TCL1 and BDCA-2, and commonly without the expression of MPO, cytoplasmic CD3, CD13, CD64, cytoplasmic CD79a, CD19 and CD20. Commonly, BPDCN is characterized by high CD123 expression, aberrant NF-κB activation, dependence on TCF4-/BRD4-network, and deregulated cholesterol metabolism. Under conventional therapy, the survival duration is only improved in a small number of BPDCN patients. Therefore, targeted therapy should be developed. Up to now, tagraxofusp is the leading edge and has been approved for BPDCN treatment. However, most of other targeted therapy agents were still not pushed to clinical trials for BPDCN. In this review, we emphatically discuss recent perspectives on BPDCN genetic features and developments of its targeted therapy.

Tagraxofusp, a novel CD123-directed cytotoxin to treat blastic plasmacytoid dendritic cell neoplasm

Tagraxofusp is a toxin-cytokine fusion protein consisting of engineered diphtheria toxin (DT) and interleukin-3 (IL-3). The IL-3 domain binds to the cluster of differentiation 123 (CD123) and translocates DT into the cytosol, which leads to cell death. Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare and aggressive hematologic malignancy with a strong expression of CD123. Historical data show that the prognosis of BPDCN is poor, with a median overall survival of 9 to 13 months. On December 21, 2018, the United States Food and Drug Administration (FDA) approved tagraxofusp for the treatment of adults and children with newly diagnosed or relapsed/refractory BPDCN, becoming the first FDA-approved drug for this disease. In this review, we examine the preclinical studies and phase I/II clinical studies that led to FDA approval of tagraxofusp, focusing on its molecular pharmacology, pharmacokinetics, efficacy and safety profile. We also discuss future directions regarding BPDCN management.

A new palliative treatment for blastic plasmacytoid dendritic cell neoplasm: a case report and review of the literature

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare haematological malignancy that derives from plasmacytoid dendritic cells. The cancer is characterized by aggressive development and dismal prognosis, and due to limited prospective study, there is currently no established standard treatment. In this study, the case of a 77-year old female patient with BPDCN, who presented with a cutaneous lesion on the right of her face, is described. The lesion developed into a serious ulcer due to rapid disease progress, thus, a surgical excision was performed. As the patient refused to receive radiotherapy or haematopoietic stem cell transplantation following surgery, a new palliative combination chemotherapy was administered, comprising gemcitabine, nedaplatin and bleomycin. The therapy gave satisfactory results in terms of short-term treatment response and was well-tolerated. Published literature regarding BPDCN is also reviewed.

Successful outcome of second allogeneic bone marrow transplantation for blastic plasmacytoid dendritic cell neoplasm with MYC locus rearrangement

A 62-year-old male was diagnosed with blastic plasmacytoid dendritic cell neoplasm (BPDCN) with a MYC rearrangement. Four months after the first unrelated bone marrow transplantation (BMT), he developed the relapsed BPDCN. After the achievement of partial remission following re-induction therapy, he underwent a second BMT from another unrelated donor, and experienced complete remission with grade II acute graft-versus-host disease and moderate chronic graft-versus-host disease. He remains alive in complete remission more than 71 months after the second BMT. These results suggested that donor change at the second transplantation may represent a considerable therapeutic option for patients with relapsed BPDCN.

Therapeutic Approaches for Blastic Plasmacytoid Dendritic Cell Neoplasm: Allogeneic Hematopoietic Cell Transplantation and Novel Therapies

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a clinically aggressive hematologic malignancy derived from precursors of plasmacytoid dendritic cells. There is no established standard therapy for BPDCN and the efficacy of conventional chemotherapy is limited, with an anticipated median overall survival ranging from 8 to 14 months. No randomized controlled trials have ever been performed to evaluate the benefit of frontline consolidation with an allogeneic hematopoietic cell transplant (allo-HCT) in BPDCN. Yet, offering an allograft has become the de facto option in BPDCN, and remains the only known long-term curative option for these patients, even in the modern era of targeted therapies. In our opinion, allo-HCT is recommended as part of frontline consolidation, especially in patients achieving first complete remission and who are deemed capable of tolerating the procedure, as published data show 3- to 4-year progression-free survival ranging from 69% to 74% in this population. Prompt referral to a transplant center, at the time of a diagnosis of BPDCN, is important to confirm allo-HCT candidacy and to initiate the process of identifying a suitable human leukocyte antigen (HLA)-compatible donor. Because disease relapse remains a major concern, additional strategies, such as post-allograft consolidation/maintenance therapy, are certainly needed to help further improve outcomes. Finally, patients deemed ineligible to receive an allo-HCT, due to lack of response and/or poor performance status, should be considered for enrollment in clinical trials.

[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。

Analysis of First-Year Twitter Metrics of a Rare Disease Community for Blastic Plasmacytoid Dendritic Cell Neoplasm (BPDCN) on Social Media: #BPDCN

PURPOSE OF REVIEW

The use of Twitter, one of the most commonly engaged social media platforms in the world, is increasing among the general public. Notably, this trend has also been observed among those involved in the healthcare field. With its ability to readily connect diverse groups of stakeholders in a given area of interest, Twitter has become a focal point for those involved in increasing awareness and information exchange in orphan disease fields. Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare, aggressive hematologic malignancy with generally poor long-term outcomes for adult patients and no standard therapeutic guidelines. Coupled with its low incidence rate, the disease has experienced a number of name changes over the past three decades (e.g., blastic NK cell lymphoma, CD4+CD56+ hematodermic tumor), thereby historically resulting in difficulties in its clinico-pathologic diagnosis and treatment approaches. All of these factors have led to a striking gap in terms of accurate information available to patients and the general public. Therefore, there is an urgent need for the development of more venues for the dissemination of information, particularly online, for this rare cancer.

RECENT FINDINGS

In this context, we began the Twitter medical community, #BPDCN, over a year ago, to help fill this information void. Now, completing its first year of existence, we aimed to analyze the metrics of Twitter use in order to better understand and to describe the characteristics and reach in of #BPDCN, and to determine the feasibility of starting and maintaining a disease-specific hashtag community in a particularly rare cancer.

Improved in vitro and in vivo activity against CD303-expressing targets of the chimeric 122A2 antibody selected for specific glycosylation pattern

Plasmacytoid dendritic cells (pDCs) play a central role for both innate and adaptive antiviral responses, as they direct immune responses through their unique ability to produce substantial concentrations of type I interferon (IFNs) upon viral encounter while also activating multiple immune cells, including macrophages, DCs, B, natural killer and T cells. Recent evidence clearly indicates that pDCs also play a crucial role in some cancers and several auto-immune diseases. Although treatments are currently available to patients with such pathologies, many are not fully efficient. We are proposing here, as a new targeted-based therapy, a novel chimeric monoclonal antibody (mAb) that mediates a strong cellular cytotoxicity directed against a specific human pDC marker, CD303. This antibody, ch122A2 mAb, is characterized by low fucose content in its human IgG1 constant (Fc) region, which induces strong in vitro and in vivo activity against human pDCs. We demonstrated that this effect relates in part to its specific Fc region glycosylation pattern, which increased affinity for CD16/FcγRIIIa. Importantly, ch122A2 mAb induces the down-modulation of CpG-induced IFN-α secretion by pDCs. Additionally, ch122A2 mAb shows in vitro high pDC depletion mediated by antibody-dependent cell-mediated cytotoxicity and antibody-dependent cellular phagocytosis. Remarkably, in vivo ch122A2 mAb efficacy is also demonstrated in humanized mice, resulting in significant pDC depletion in bloodstream and secondary lymphoid organs such as spleen. Together, our data indicates that ch122A2 mAb could represent a promising cytotoxic mAb candidate for pathologies in which decreasing type I IFNs or pDCs depleting may improve patient prognosis.

A Challenging Blastic Plasmacytoid Dendritic Cell Neoplasm Case: Tough Decisions to Make

Blastic plasmacytoid dendritic cell neoplasm is a very rare disease and in our case report we discuss the presentation of our patient, her treatment and response in addition for a discussion of the newly therapeutic options that are available.

Clinical features and treatment outcomes of blastic plasmacytoid dendritic cell neoplasm: a single-center experience in Korea

BACKGROUND/AIMS

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare hematologic malignancy that typically presents in the form of skin manifestations with or without lymph node and bone marrow involvement. Given its rarity and recent recognition as a distinct pathological entity, no standard of treatment exists for this aggressive disease and its prognosis is particularly dismal.

METHODS

We retrospectively analyzed clinical features and treatment outcomes of patients who were diagnosed with BPDCN between 2000 and 2014.

RESULTS

Ten patients had a median age at diagnosis of 41 years (range, 18 to 79), and seven patients were male. Sites of disease involvement were the skin (n = 7), lymph node (n = 5), bone marrow (n = 2), liver (n = 2), spleen (n = 2), and soft tissue (n = 1). Intensified chemotherapy regimens such as hyperCVAD regimen (cyclophosphamide, vincristine, doxorubicin, dexamethasone, methotrexate, cytarabine), and VPDL (vincristine, methylprednisolone, daunorubicin, L-asparaginase) were used as a first-line treatment. Although all patients treated with intensified chemotherapy showed an objective response (five patients with complete response) with median progression-free survival of 11.2 months (range 6.2 to 19.4), complete remission was not sustained for more than 2 years in any case. The response was relatively long-lived compared with previously reported CHOP (doxorubicin, cyclophosphamide, vincristine, prednisone)-like regimens, but the above regimens do not result in long-term remission.

CONCLUSIONS

All patients treated with hyperCVAD or VPDL showed an objective response, but the duration of response was relatively short. Thus, the development of more effective induction as well as consolidation treatment strategy should be warranted to improve this rare disease entity.

CD4-Negative Variant of Cutaneous Blastic Plasmacytoid Dendritic Cell Neoplasm With a Novel PBRM1 Mutation in an 11-Year-Old Girl

OBJECTIVES

We report a rare case of CD4- cutaneous blastic plasmacytoid dendritic cell neoplasm (BPDCN) with a novel PBRM1 mutation.

METHODS

An 11-year-old girl presented with an enlarged mass on her left arm and underwent an incisional biopsy.

RESULTS

Histopathologic examination and immunohistochemistry studies showed a monotonous proliferation of blasts that were CD4-, CD56+, and CD123+. There was no evidence of leukemic dissemination. Next-generation sequencing detected PBRM1 and CIC gene abnormalities. We confirmed and validated a novel PBRM1 mutation by conventional polymerase chain reaction and Sanger sequencing.

CONCLUSIONS

CD4- variant of BPDCN may be mistaken for myeloid sarcoma or extramedullary lymphoblastic leukemia/lymphoma because of their overlapping morphologic and immunophenotypic features; thus, a careful clinicopathologic evaluation is essential to reach the correct diagnosis. PBRM1 mutation seems to be a driver event in this case. Our study underscores the importance of alterations in chromatin remodeling in the pathogenesis of BPDCN.

A critical review of treatment modalities for blastic plasmacytoid dendritic cell neoplasm

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a clinically aggressive tumor derived from the precursors of plasmacytoid dendritic cells. It is a rare disease presenting across all ages with either skin or both skin and bone marrow involvement often conferring a poor prognosis. Though localized radiation has been used before, acute leukemia based regimens, remains the treatment of choice for induction of remission. Hematopoietic stem cell transplant, either autologous or allogeneic, is further required for attaining sustained remissions. Recently, a number of targeted therapies and newer drugs have been used as the molecular and genetic understanding of the disease have improved.

Blastic Plasmacytoid Dendritic Cell Neoplasm: Analysis of Clinicopathological Feature and Treatment Outcome of Seven Cases

BACKGROUND

Blastic plasmacytoid dendritic cell neoplasm (BPDCN), which is derived from the precursor of plasmacytoid dendritic cells, is a rare and highly aggressive hematologic malignancy. It has only recently been recognized as a distinct entity. BPDCN characteristically has a predilection for cutaneous involvement.

OBJECTIVE

The aim of this study was to describe the clinical and pathological features of BPDCN, and to review the treatment courses to analyze the prognosis and the optimal therapeutic approach.

METHODS

We retrospectively reviewed seven BPDCN cases registered in the Samsung Medical Center database between January 2010 and December 2014.

RESULTS

The median age of the patients was 52 years (range, 18~79 years), and six patients were male. The clinical staging was as follows: skin (n=5), lymph node (n=6), bone marrow (n=4), and peripheral blood (n=2). The skin manifestations were bruise-like tumefaction (n=4), erythematous nodule (n=4), or multiple erythematous papules (n=1). The pathological evaluation revealed dense diffuse or nodular infiltration of neoplastic cells, which were positive for CD4, CD56, and CD123 in the immunohistochemical analysis. Six patients received multiagent chemotherapy as the first-line treatment, alone (n=4), or followed by stem cell transplantation (SCT, n=1) or concurrent radiotherapy (n=1). The median progression-free survival after the first-line treatment was 6 months (range, 2~12 months).

CONCLUSION

Three different skin manifestations were observed, with pathological features analogous to each other. All patients who received chemotherapy without SCT achieved partial or complete response but experienced relapse. Furthermore, they showed various clinical courses irrelevant to the cutaneous involvement.

Blastic plasmacytoid dendritic cell neoplasm: skin and bone marrow infiltration of three cases and the review of the literature

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a distinct and rare neoplastic entity and was classified as a subgroup of acute myeloblastic leukemia by the WHO in 2008. The median survival of patients was 15.2 months in a large case series. Allogeneic or autologous bone marrow transplantation has been recommended by some reports because of the disease's poor prognosis. We present three patients who presented with both skin and bone marrow infiltration. A 57-year-old man, a 62-year-old woman, a 64-year-old man were admitted to our outpatient clinic because of skin lesions. All of the patient's had bone marrow infiltration with positivity of the CD4, CD56, and CD123 staining. Survival of the patient's were 42, 6 and 12 months, respectively. Two of the patients who presented as blastic form didn't respond to any chemotherapy. BPDCN is a difficult disease to diagnosis and manage. CD4, CD56, CD123, CD303, and T cell leukemia/lymphoma 1. Cutaneous lesions can present as isolated nodules, macules, and disseminated macules and nodules. Positivities are crucial to the diagnosis of the disease in histological examination. Bone marrow infiltration or disease relapse at presentation were related to poor prognosis. Complete immunocytochemical staining must be performed for all patients who have cutaneous lesions with or without blood count abnormalities. Bone marrow (allogeneic or autologous) transplantation should be considered at the first remission.

A case of blastic plasmacytoid dendritic cell neoplasm with ecchymotic lesions on the whole body

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) derived from plasmacytoid dendritic cell precursors is a very rare, and characterized by cutaneous and bone marrow involvement and leukemic spread. The neoplasm presents with an aggressive behavior, and the clinical findings include cytopenia, particularly thrombocytopenia. The tumor cells are negative for antigens of T- and B- cell lines. However, these cells express CD4, CD56 and CD123, which are markers of plasmacytoid dendritic cells, and negative for Epstein-Barr virus (EBV). From this point of view, a 71-year-old man who was initially found to have a cutaneous mass on his face and thorax was reported here, and initially was diagnosed as "eczema". The skin rashes then became aggravated on a trial of low dose topical corticosteroid for 2 months. According to skin biopsy, the tumor cells reveal an immature blastic appearance and positive for CD4 and CD56, negative for CD3, CD20, indicating a diagnosis of BPDCN. Here, we report the dismal course of a patient with BPDCN without accepting further therapy, and only survived 3 months.

Sustained complete remission of a limited-stage blastic plasmacytoid dendritic cell neoplasm followed by a simultaneous combination of low-dose DeVIC therapy and radiation therapy: a case report and review of the literature

The patient was a 74-year-old man who was found to have a cutaneous mass on his left shoulder in February 2012. Because the mass bled easily and was tending to grow, total resection of the cutaneous tumor, which measured approximately 5 cm x 3 cm, was performed in July. Histopathological examination revealed a tumor that extended from the dermis to the cutaneous adipose tissue, but no invasion of the epidermis was seen. The tumor cells were plasmacytoid cells ranging in size from small to intermediate, and there was no nuclear irregularity. They had a high nuclear-cytoplasmic ratio, and nucleoli were observed. The tumor cells were CD4-positive, CD56-positive, and CD123-positive, and they were AE1/AE3-negative, CD3-negative, CD20-negative, and myeloperoxidase-negative. (18)F-fluorodeoxyglucose positron emission tomography-computed tomography (FDG-PET/CT), a bone marrow examination, etc., were performed, but no lesions were detected at other sites. Based on the above findings a diagnosis of blastic plasmacytoid dendritic cell neoplasm (BPDCN), Stage IEA, was made. Because the patient had limited-stage BPDCN and was elderly, we treated him with a simultaneous combination of low-dose DeVIC (dexamethasone, VP16, ifosfamide, and carboplatin) therapy and local radiation therapy (LRT) and sustained a complete remission for approximately 1 year. Simultaneous combination of non-CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) chemotherapy and LRT appeared to be useful in the treatment of limited-stage BPDCN even in the elderly.

Blastic plasmacytoid dendritic cell neoplasm presenting as fever with diffuse cutaneous nodules

A young man, presented with high-grade fever and disseminated asymptomatic skin lesions of 6-weeks duration. Cutaneous examination revealed multiple infiltrated monomorphic skin-colored papules and nodules upto 2×2 cm all over scalp, face, trunk and extremities. Light microscopy of nodules showed diffuse infiltration of dermis and subcutis by a tumor composed of medium to large cells with round to ovoid nuclei with fine chromatin, few with visible nucleoli and scanty to moderate amounts of eosinophilic cytoplasm. Tumor cells were positive for CD4, CD8, CD56 and negative for CD30, terminal deoxynucleotidyl transferase and Alk-1. Excised axillary lymph node showed similar morphologic and immunohistochemical findings. There was bone marrow involvement with infiltrate of large atypical/immature lymphoid cells. Diagnosis of blastic plasmacytoid dendritic cell neoplasm was made. This is a rare neoplasm. presenting commonly in the skin, with or without concurrent extracutaneous disease.