Control effect of Dasatinib on the treatment of acute myeloid leukemia and adverse events of CD123 targeting CAR-T:a case report and literature review / 陆军军医大学学报

Objective To preliminarily explore the efficacy of chimeric antigen receptor T cells(CAR-T)targeting CD 123 in the treatment of acute myeloid leukemia(AML)and the role of dasatinib in the treatment of CD123 targeting CAR-T induced side effects.Methods Clinical data of 1 patient with relapsed AML admitted to No.920 Hospital of PLA Joint Logistic Support Force in September,2019 were collected.The patient relapsed after previous multi-line chemotherapy and was treated with CD123 targeting CAR-T therapy.The routine blood changes of the patient after treatment were observed.Dasatinib was used when agranulocytosis occurred,40 mg orally 3 times per day,and was stopped when agranulocytosis was relieved.Changes in blood cells,CAR-T amplification,and disease control were observed.The patient was followed up for over 1 year.Results Flow cytometry for bone marrow showed that minimal residual disease negative result was observed in 30 d after infusion.The patient remained disease-free for over 1 year.After CD 123 CAR-T cells infusion,significant expansion of CAR-T cells was observed,accompanied by granulocyte deficiency and cytokine release syndrome(CRS).After using dasatinib,inhibition of CAR-T cell expansion was observed,accompanied by blood cell recovery,and CRS symptoms were alleviated.After stop of dasatinib,CAR-T cells expanded again and blood cells decreased again.Conclusion CAR-T cells targeting CD 123 have certain efficacy in the treatment for relapsed AML.Dashatinib has a blocking effect on the amplification and function of CAR-T,which can alleviate bone marrow suppression caused by CD 123 targeting CAR-T and avoid severe CRS.

Blastic plasmacytoid dendritic cell neoplasm: A clinico-pathological retrospective analysis of thirteen cases / 北京大学学报(医学版)

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.

Construction of a new anti-CD123 chimeric antigen receptor T cells and effect of anti-acute myeloid leukemia / 中华血液学杂志

Objective: To construct a new CD123- specific chimeric antigen receptor in order to provide a foundation for immunotherapy of CD123 positive leukemia. Methods: A hybridoma strain (6E11) capable of stably secreting CD123 antibody was obtained by a monoclonal screening technique, and the hybridoma cells were expanded and injected intraperitoneally to the pretreated Balb/c mice. Ascites was collected and purified to obtain the monoclonal antibody (mAb) . The affinity and specificity of 6E11 mAb were measured. The variable regions of the heavy and light chains of the 6E11 mAb were cloned by RT-PCR from the 6E11 mouse hybridoma. We generated a new CD123 specific chimeric antigen receptor with a scFv fragment derived from 6E11 antibody, designated as 6E11 CAR. T cells were transduced with lentiviral supernatant from 293T cells transfected with 6E11 CAR plasmid to generate 6E11 CAR-T cells. The specific cytotoxicity of 6E11 CAR-T against CD123(+) acute myeloid leukemia (AML) cell lines and primary AML cells in vitro were evaluated by co-culture experiments, degranulation experiments and cytokine releasing assay. Results: ① A hybridoma cell line 6E11 stably secreting anti-human CD123 antibody was developed and its variable region sequences were obtained. ② The 6E11 mAb has high affinity for CD123 protein (Kd value: 2.1 nmol/L) . The 6E11 mAb specifically recognizes CD123(+) cell line THP-1 cells and does not respond to CD123(-) cell line Jurkat cells. ③ 6E11 CAR-T cells were successfully generated with a CAR expression rate higher than 60%. ④ 6E11 CAR-T cells could specifically kill CD123(+) MV4-11 cell line but had no killing effect on the CD123(-) K562 cell line. Compared with vector-T cells, 6E11 CAR-T cells have higher killing rate to MV4-11 cells[ (98.60±1.20) %vs (20.28±6.74) %, P<0.001]. ⑤ MV4-11 cells activated 6E11 CAR-T cells significantly but not Vector-T cells[ (26.33±3.30) %vs (1.17±0.06) %, P<0.001]. ⑥ 6E11 CAR-T cells released more cytokines than vector-T cells when co-cultured with MV4-11[IL-2: (92.90±1.51) pg/ml vs (6.05±3.41) pg/ml, P<0.001; TNF-α: (1 407.20±91.95) pg/ml vs (7.86±0.85) pg/ml, P<0.001; IFN-γ: (5 614.60±170.17) pg/ml vs (8.42±2.70) pg/ml, P<0.001]. The IFN-γ, IL-2 and TNF-α in the 6E11 CAR-T group were similar to those in the Vector-T group when co-cultured with K562. ⑦ 6E11 CAR-T cells could be activated by bone marrow mononuclear cells (BMMNC) derived from CD123(+) AML patients and effectively kill these BMMNC cells from CD123(+) AML patients. Conclusion: 6E11 hybridoma cell line can stably secrete highly specific monoclonal antibodies against human CD123, which can be used to detect the expression of human CD123. It can also be used to target human CD123 protein in tumor immunotherapy. CD123 CAR-T cells with 6E11 Ig variable region sequence have specific anti-leukemic activity in vitro, which may provide a new option for further clinical research of AML.

Expressions of CD34, CD123 and CD38 in acute myelogenous leukemia and their clinical significances / 白血病·淋巴瘤

Objective To investigate the expressions of CD34, CD123 and CD38 in acute myelogenous leukemia (AML) and their clinical significances. Methods A total of 164 patients with AML in Xiangya Hospital of Central South University from February 2014 to July 2015 were enrolled. Cellular immunophenotyping was performed by flow cytometry. According to the expressions of CD34, CD38 and CD123, 164 patients were divided into positive group and negative group, and the clinical data and immature cells ratio of two groups were compared. Results In 164 patients with AML, 102 cases (62.2 ％) were CD34 positive, 126 cases (76.8％) were CD123 positive, and 144 cases (88.3％) were CD38 positive. There were no significant differences in age and sex between the positive and negative groups (P> 0.05). But there were significant differences in the proportion of immature cells, white blood cell count and hemoglobin between the two groups (all P< 0.05). The expression rates of CD34, CD38 and CD123 were correlated with minimal residual disease and complete remission rate (all P< 0.05). Conclusions CD34, CD123 and CD38 are effective markers for AML detection. The expressions of CD34, CD123 and CD38 can be used as the judgment marker of cell maturity, which is conducive to the determination of the condition and prognosis of AML patients.

Progress of CD123 chimeric antigen receptor T cells in treatment of acute myeloid leukemia / 白血病·淋巴瘤

Acute myeloid leukemia (AML) is the most common type of leukemia at present. Although clinical treatment has a certain effect on this disease, most patients still die of relapse or its treatment related diseases. Nowadays, chimeric antigen receptor (CAR) T cells therapy technology has developed rapidly, and has become a hot topic in tumor immunotherapy. The high expression of CD123 in AML cells, low expression or non expression in normal hematopoietic stem cells and tissues, make more and more researchers focus on the technology of CD123+cell immunotherapy. Some studies have confirmed that CD123 CAR-T cells have a certain effect on AML, which provides a new way for clinical treatment of relapsed or refractory AML. This review summarizes the structure, production and delivery methods of CD123 CAR-T cells, and the current research status and shortcomings of CD123 CAR-T cells.

Quantitative flow cytometric evaluation of CD200, CD123, CD43 and CD52 as a tool for the differential diagnosis of mature B-cell neoplasms

Abstract Background Distinction between mature B-cell neoplasms can be difficult due to overlapping of immunologic features and clinical manifestations. This study investigated whether quantifying mean fluorescence intensity of four monoclonal antibodies in a flow cytometry panel is useful for the differential diagnosis and characterization of these disorders. Methods The expressions of CD52, CD200, CD123 and CD43 were analyzed in samples from 124 patients with mature B-cell neoplasms. The quantitative estimation of these antigens was assessed by mean fluorescence intensity. Results The cases included were 78 chronic lymphocytic leukemias, three atypical chronic lymphocytic leukemias, six marginal zone lymphomas, 11 splenic marginal zone lymphomas, nine lymphoplasmacytic lymphomas, six mantle cell lymphomas, two hairy cell leukemias, two hairy cell leukemias variant, five follicular lymphomas, one Burkitt lymphoma and one diffuse large B-cell lymphoma. The mean fluorescence intensity of CD200 was higher in atypical chronic lymphocytic leukemia, chronic lymphocytic leukemia and hairy cell leukemia cases. CD123 showed higher mean fluorescence intensities in hairy cell leukemia cells. Chronic lymphocytic leukemia, atypical chronic lymphocytic leukemia and mantle cell lymphoma had higher expression of CD43 and all follicular lymphoma cases had very low mean fluorescence intensity values. CD52 expression was consistently positive among all cases. Conclusion Quantitative evaluation of these markers can be a useful additional tool to better identify some types of mature B-cell neoplasms.

Preparation of CD123 mono-antibody modified tanshinone ⅡA loaded immunoliposome and its in vitro evaluation / 中国中药杂志

In the study, we developed a novel formulation, CD123 mono-antibody (mAb) modified tanshinone ⅡA loaded immunoliposome (CD123-TanⅡA-ILP) to achieve the targeted drug delivery for leukemia cells. Orthogonal test was used to optimize liposome preparation, and the TanⅡA-loaded PEGylated liposomes (TanⅡA-LP) of S100PC-Chol-(mPEG2000-DSPE)-TanⅡA at 19∶5∶1∶1 molar ratio were prepared by the thin film hydration-probe ultrasonic method. A post-insertion method was applied to prepare CD123-TanⅡA-ILP via thiolated mAb conjugated to the terminal of maleimide-PEG2000-DSPE. The cellular uptake assay was measured by flow cytometry, and the inhibitory effect of CD123-TanⅡA-ILP on NB4 cells proliferation was tested by using MTT assay. The results of cellular uptake assay showed that CD123-ILP could significantly increase the drug uptake of NB4 cells as compared with free drugs and LP. The IC₅₀ values at 48 h incubation were 20.87, 11.71, 7.17 μmol•L⁻¹ respectively for TanⅡA，TanⅡA-LP and CD123-TanⅡA-ILP. CD123-ILP demonstrated a potential and promising targeted drug delivery strategy for acute myelogenous leukemia (AML) treatment.

The study of expression and prognostic value of CD123 in acute myeloid leukemia bone marrow blasts / 中华血液学杂志

Objective@#To study the expression of CD123 in bone marrow (BM) blasts of acute myeloid leukemia (AML) patients to explore the relationship between CD123 expression and therapeutic response and prognosis.@*Methods@#This study retrospectively analyzed expression and distribution of CD123 in BM blasts in 137 cases of newly diagnosed AML (excluded M3) , CD123 detected by flow cytometry≥20% was defined as positive, including 84 CD123+ AML and 53 CD123- AML, efficacy and prognosis were compared between the two groups.@*Results@#① Among 137 patients, 84 were in group CD123+ (61.3%) , and 53 in group CD123- (38.7%) . All 137 patients were classified into risk groups based on cytogenetic and molecular biology abnormalities. No significant differences were seen between the three risk groups with regard to their CD123 levels (χ2=0.861, P=0.650) . Compared with CD123- group, the CD123+ group had higher WBC[47.7 (1.0-264.0) vs 22.4 (0.7-211.0) , z=-2.592, P=0.010]. ② The rates of first complete remission (CR1) and recurrence of CD123+ group were 54.8% (46/84) and 50.8% (32/63) , respectively; and CD123- group were 73.6% (39/53) and 41.7% (20/48) , respectively. There was significant difference of CR1 between the two groups (χ2=5.121, P=0.027) , whereas no significant difference of the recurrence rate (χ2=0.911, P=0.340) . ③ The median dutations of OS between CD123+ group and CD123- group were 20.0 (95%CI 13.1-26.9) months vs 44.0 (95%CI 23.6-47.3) months, respectively (χ2=5.874, P=0.015) ; The median durations of DFS were 7.8 (95%CI 1.4-14.1) months vs 18.6 (95%CI 0-39.7) months, respectively, no differences were observed between the two groups (χ2=2.939, P=0.086) . ④ CD123 retained an adverse prognosis value on DFS and OS within the intermediate group and patients ≤ 50 years older.@*Conclusions@#CD123 widely expressed in AML patients, which was an independent risk factor for CR1 and OS, which implicating its important role in evaluating the induction chemotherapy response and prognosis of AML.

Impact on the Expression of CD123 on K562 Cells Induced by rhIFN-γ / 昆明医科大学学报

Objective To investigate the inhibitory effect of rhIFN-γ on human chronic myeloid leukemia cell line K562,and the impaction on the expression of CD123.Methods MTT method was used to test cell relative viability with rhIFN-γ at different concentrations.The expression of CD123 on K562 ceils was detected by flow cytometry.Results The relative inhibition of K562 cells proliferation was hampered when the cells were treated with rhIFN-γ for 72 h at the concentration of 5 x 10P ～ 108 U/L,respectively.However,rhIFN-γ at 2 x 105 U/L was benefit to K562 cells proliferation.After treatment with rhIFN-γ at 0,2 x 105 U/L and 107 U/L,the percentages of CD123 expression on K562 cells were (4.10 ± 1.46) ％,(7.2 ± 2.50) ％ as well as (21.6 ± 1.17) ％,respectively.Compared with the control group,107 U/L rhIFN-γ significantly increased the expression of CD123 on K562 cells (P＜0.05).Conclusion The effect of rhIFN-γ on the growth of K562 cells has two aspects (inhibition or proliferation),and it can increase the expression of CD 123.

Research progress of T cells expressing CD123 chimeric antigen receptor for treatment of AML / 中国药理学通报

Acute myeloid leukemia ( AML) is the most common acute leukemia in adults and has the highest death rate of all leukemias. Compared with other hematologic malignancies , there was only a small increment in the 5-year relative overall survival for patients with AML in the last 40 years, despite the advancement in our understanding of AML .CD123 is an AML-associated antigen that expresses at a high level in leukemic stem cells and leukemic blasts and a low level in normal hematopoiet-ic stem cells.As an attractive surface target for AML therapies , immune-based therapies targeting CD 123 are being developed re-cently, especially chimeric antigen receptor ( CAR) T-cell-based immunotherapy .Preclinical data have demonstrated that CD 123 CAR-T cells exhibit potent antileukemic activity and various im-pacts on normal hematopoiesis .This will probably be a promis-ing treatment for patients with relapsed/refractory AML.

Blastic plasmacytoid dendritic cell neoplasm: Report of two pediatric cases.

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare subtype of acute leukemia that typically follows a highly aggressive clinical course in adults, whereas experience in children with this disease is very limited. We report cases of two children in whom bone marrow showed infi ltration by large atypical monocytoid ‘blast-like’ cells which on immunophenotyping expressed CD4, CD56, HLA-DR and CD33 while were negative for CD34 other T-cell, B-cell and myeloid markers. The differential diagnoses considered were AML, T/NKcell leukemia and acute undifferentiated leukemia. Additional markers CD303/ BDCA-2 and CD123 which are recently validated plasmacytoid dendritic cell markers were done which helped us clinch the diagnosis of this rare neoplasm. An accurate diagnosis of BPDCN is essential in order to provide prompt treatment. Due to its rarity and only recent recognition as a distinct clinicopathological entity, no standardized therapeutic approach has been established for BPDCN.

Investigating Cell Surface Markers on Normal Hematopoietic Stem Cells in Three Different Niche Conditions

Hematopoietic stem cells are of therapeutic interest to the clinicians and researchers due to their promising assistance in management of malignant and inherited hematological conditions. Evaluation of cell surface markers using multiparametric flow cytometry is a well adapted qualitative measure of cells in question for many years. An artillery of these markers has been studied in hematological malignancies and related disorders. However, their role and differential expression on normal hematopoietic stem cells from clinically available sources is not always described carefully. In the present study, we attempted to evaluate expression of CD44, CD90, CD96 and CD123 in three clinically available sources of normal HSCs (Hematopoietic stem cells). Sources of HSCs in the present study involved umbilical cord blood (UCB), normal bone marrow (NBM) and bone marrow from idiopathic thrombocytopenic purpura (ITP) patients (IBM). CD44 is an important homing receptor while CD90 is involved in maintaining stem cell quiescent. CD96 is known to be leukemia specific marker and CD123 is involved in stem cell differentiation and survival. We observed a significant difference in expression CD44, CD90 and CD123 on normal HSCs derived from umbilical cord and ITP marrow. CD96 was highly expressed on HSCs obtained from ITP marrow. Investigating expression of these markers on normal HSCs in different niches will be helpful in correlating their function with niche condition and delineating their 'abnormal' expression from the normal.

CD63 e CD123 expressão, autoanticorpos IgG e acurácia do teste do soro autólogo em pacientes com urticária crônica / CD63 and CD123 expression, IgG autoantibody and accuracy of autologous serum test in patients with chronic urticaria

INTRODUÇÃO: Na urticária crônica (UC), o teste cutâneo do soro autólogo (TCSA) pode sugerir a etiologia autoimune. Recentemente, uma nova técnica laboratorial denominada teste de ativação de basófilos (TAB) vem sendo utilizada para esse diagnóstico. OBJETIVOS: Analisar o TCSA em relação ao TAB, assim como avaliar os receptores da interleucina 3 (IL3) (CD123) e a presença de autoanticorpos da classe de imunoglobulina G (IgG) inespecíficos ligados aos basófilos de pacientes com UC. MÉTODOS: Estudamos 33 adultos com UC espontânea com idade média de 42,5 + 14 anos. Por meio da citometria de fluxo foi feita a análise da expressão das moléculas CD63 em basófilos de um doador atópico após o estímulo pelo soro dos pacientes com UC. Também realizamos a pesquisa da expressão da molécula CD123 e de autoanticorpos IgG inespecíficos. RESULTADOS: O odds ratio (OR) entre o TCSA e o TAB foi de 1 (intervalo de confiança [IC] 95 por cento: 0,22-4,5). O TCSA para o diagnóstico da UC autoimune mostrou acurácia de 54,5 por cento, sensibilidade de 66 por cento, especificidade de 33 por cento, valor preditivo positivo de 63 por cento e valor preditivo negativo de 36 por cento. Não houve diferença estatística entre os grupos estudados quanto à média de expressão dos anticorpos IgG inespecíficos e das moléculas CD123 (para um p < 0,05). DISCUSSÃO: Este estudo demonstrou baixa precisão do TCSA no diagnóstico da UC autoimune; o grupo de pacientes com TCSA positivo não mostrou diferença estatística em relação ao grupo com TCSA negativo nos demais aspectos analisados. CONCLUSÃO: Pelos poucos estudos existentes e pela relevância do assunto, acreditamos na necessidade de mais estudos abordando esses aspectos.

INTRODUCTION: The autologous serum skin test (ASST) may suggest an autoimmune etiology in chronic urticaria (CU). A new laboratory technique called basophil activation test (BAT) has been currently employed for its diagnosis. OBJECTIVE: To analyze ASST in relation to BAT as well as to evaluate interleukin 3 (IL3) receptors (CD123) and non-specific immunoglobulin G (IgG) autoantibodies bound to basophils in patients with chronic urticaria. METHODS: We studied 33 adults with CU and mean age of 42.5 + 14 years. After stimulation by serum from patients with CU, CD63 expression on basophils from one atopic donor was analyzed by flow cytometry. Furthermore, we investigated CD123 and IgG autoantibody expressions. RESULTS: The odds ratio (OR) between ASST and BAT was 1.00 (95 percent confidence interval [CI]: 0.22 to 4.5). The ASST for autoimmune CU diagnosis showed an accuracy of 54.5 percent, sensitivity of 66 percent, specificity of 33 percent, positive predictive value of 63 percent, and negative predictive value of 36 percent. There was no statistical difference between the studied groups as to mean non-specific IgG and CD123 expressions (for a p < 0.05). DISCUSSION: This study demonstrated that ASST has low accuracy in the diagnosis of autoimmune CU. Concerning other analyzed aspects, there was no statistical difference between positive ASST and negative ASST. CONCLUSIONS: Due to insufficient studies in this area and the relevance of this issue, further investigation is required.

Isolation and identification of leukemia stem cells from acute myeloid leukemia patients / 白血病·淋巴瘤

Objective To isolate and identify leukemia stem cells from acute myeloid leukemia patients for further research. Methods By Ficoll density gradient centrifugation, mononuclear cells were firstly separated from bone marrow of patients. According to specific surface markers, CD+34 CD+123 of leukemic stem cells were sorted by flow cytometer. Their ability of self-renewal and differentiation were evaluated by colony formation and cobblestone forming ability. At the same time, the purity and cell morphology of CD+34 CD+123 cells was analysed. Results Comparared with total mononuclear cells, the proportion of the CD+34 CD+123 cells after sorting was 10.7 %, and these cells showed the ability of colony forming and cobblestone forming, and the purity proportion of CD+34 CD+123 cells was 62.1%. Conclusion The leukemia stem cells were isolated successfully and could be used in further study.

CD4-/CD56+/CD123+ Hematodermic Neoplasm Showing Early Liver Metastasis

Hematodermic neoplasm (HN) is a clinically aggressive neoplasm with a high incidence of cutaneous involvement and a risk of leukemic dissemination. In the recent WHO-EORTC classification, the term blastic natural killer cell lymphoma has been replaced with CD4+/CD56+ HN because of its derivation from a plasmacytoid dendritic cell precursor. Cases of HN that completely lack CD4 or CD56 expression, therefore represents a diagnostic problem. A 68-year-old Korean male was diagnosed with CD4-/CD56+ HN and treated with hyper-CVAD (cyclophosphamide, vincristine, doxorubicin, dexamethasone) at initial treatment, and then switched to high dose methotrexate/cytarabine. His disease relapsed and resulted in death from bone and brain disease 6 months after complete clinical remission, despite diagnostic workups, including a radioisotope liver scan and ultrasound-guided fine needle aspiration biopsy. Further cytogenetic studies such as comparative genomic hybridization could elucidate the genetic mechanisms in the development and progression of lymphomas. We report an unusual case of 'CD4-/CD56+/CD123+ HN' showing early liver metastasis.

Neoplasia hematodérmica CD4+ CD56+ en la infancia / Hematodermic CD4+ CD56+ neoplasm in childhood

La neoplasia hematodérmica CD4+ CD56+ con fenotipo de célula dendrítica plasmocitoide es una rara y agresiva neoplasia recientemente reconocida por la WHO-EORTC classification. Afecta adultos de edad media y ancianos, siendo muy pocos los casos descriptos en niños. Presentamos el caso de una niña de 12 años con grave retraso mental, estigmas genéticos y múltiples lesiones cutáneas localizadas en miembros inferiores y superiores. Histológicamente se observó un infiltrado dérmico difuso de células pequeñas y medianas con expresión de CD4, CD56, CD43 y S100 así como de marcadores dendríticos plasmocitoides: CD 123 y BDCA-2 confirmados por citometría de flujo, sin compromiso de sangre periférica ni médula ósea. Cumpliendo dos semanas de tratamiento para leucemia linfoblástica aguda evolucionó con remisión clínica de las lesiones cutaneas.

Hematodermic CD4+ CD56+ neoplasm with plasmacytoid dendritic cell phenotype is a rare and aggressive neoplasm recently recognized by the WHO-EORTC classification. It generally appears in elderly adults, exceptionally in childhood. We present a 12-year-old girl with severe mental retardation, genetic clinical features and multiple nodular cutaneous lesions on legs and arms. Histologically the nodules showed diffuse dermal infiltrate of medium and small cells and expression of CD4, CD56, CD43, S100 and plasmacytoid dendritic markers: CD123, BDCA-2 under flow cytometry study. Peripheral blood and bone marrow were not involved. Clinical remission of cutaneous lesions was observed after two weeks of acute lymphoblastic leukemia therapy.