Blastic plasmacytoid dendritic cell neoplasm: the first report of two cases treated by 5-azacytidine.

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare hematologic malignancy which was first included as an independent cutaneous lymphoma in the 2008 World Health Organisation (WHO) classification (1). BPDCN usually has an extremely poor prognosis, with quick relapses after chemotherapy (2; 3). Here, we report two cases of patients diagnosed in 2011 with BPDCN and myelodysplasia, and who were treated for the first time with 5-azacytidine (5-Aza); a drug approved by the Food and Drug Administration (FDA) and mainly used in the treatment of myelodysplastic syndrome (Kaminskas E, et al. 2005 Clin Cancer Res, 11, 3604-8). The first case was an 81-year-old man who presented with unusual CD10+, CD56- immunohistochemistry and 45X, -Y abnormality using fluorescent in situ hybridization (FISH) analysis. The second case was a 78-year-old woman who manifested monosomy 13 and chromosome instability due to D13S319 locus deletion in 13q14 as determined by FISH. Both patients showed excellent responses of their skin lesions after one cycle of chemotherapy, and their hematological disease was stabilized; however, pulmonary sepsis set in, followed by neutropenia after the fourth and the fifth cycle of treatment, that is, eight and 9 months postdiagnosis, respectively, leading to patient death.

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.

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.