Acute myeloid dendritic cell leukaemia with specific cutaneous involvement: a diagnostic challenge

Blastic plasmacytoid dendritic cell leukemia successfully treated by autologous hematopoietic stem cell transplantation to a remission of 48-month duration

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a very rare subtype of AML characterized by the clonal proliferation of precursors of plasmacytoid dendritic cells. It presents with an aggressive behavior. The clinical findings include cytopenia, particularly thrombocytopenia. Although it responds well to chemotherapy initially, the relapse is a rule and prognosis is very poor. There is limited data published in the literature, making it very problematic to define the biological and clinical features, hence, the appropriate therapeutic approach. There are various treatment methods such as multiagent chemotherapy based on ALL or AML and/or hematopoietic stem cell transplantation. However, none of them is approved as a standard therapy. From this point of view, we herein report a 20-year-old case at onset of a leukemic form of BPDCN who survived 48 months after autologous hematopoietic stem cell transplantation.

Blastic plasmacytoid dendritic cell neoplasm with leukemic presentation: an Italian multicenter study

The objective of this study was to evaluate the clinical features, prognostic factors, and efficacy of treatments in patients with blastic plasmacytoid dendritic cell neoplasm with a leukemic presentation at onset of the disease. In order to do this, a retrospective multicenter study was performed from 2005-2011 in 28 Italian hematology divisions in which 43 cases were collected. Forty-one patients received an induction therapy, consisting of an acute myeloid leukemia-type regimen in 26 patients (60%) and acute lymphoid leukemia/lymphoma-type regimen in 15 patients (35%). Six patients (14%) underwent allogeneic hematopoietic stem cell transplantation. Seventeen patients (41%) achieved a complete remission: seven after acute myeloid leukemia-type treatment and 10 after an acute lymphoid leukemia/lymphoma-type regimen, with a significant advantage for acute lymphoid leukemia/lymphoma-type chemotherapy (P=0.02). Relapse occurred in six of the 17 patients (35%) who achieved complete remission, more frequently after acute lymphoid leukemia/lymphoma-type chemotherapy. The median overall survival was 8.7 months (range, 0.2-32.9). The patients treated with an acute myeloid leukemia-type regimen had an overall survival of 7.1 months (range, 0.2-19.5), whereas that of the patients receiving acute lymphoid leukemia/lymphoma-type chemotherapy was 12.3 months (range, 1-32.9) (P=0.02). The median overall survival of the allogeneic hematopoietic stem cell transplant recipients was 22.7 months (range, 12-32.9), and these patients had a significant survival advantage compared to the non-transplanted patients (median 7.1 months, 0.2-21.3; P=0.03). In conclusion, blastic plasmacytoid dendritic cell neoplasm with bone-marrow involvement is an aggressive subtype of high-risk acute leukemia. The rarity of this disease does not enable prospective clinical trials to identify the better therapeutic strategy, which, at present, is based on clinicians' experience.

Blastic plasmacytoid dendritic cell neoplasm: a report of four cases and review of the literature

BACKGROUND

Blastic plasmacytoid dendritic cell neoplasm (BPDCN), formerly known as agranular CD4(+) /CD56(+) haematodermic neoplasm (CD4/CD56 HN), is a rare distinct form of lymphoma-like entity known of dermatologists because of its marked predilection for cutaneous involvement, and its aggressive behaviour. Moreover, the association or the evolution to an acute leukaemia entity that still expresses CD4 and CD56 markers is almost systematic. This new described entity of 'CD4(+) /CD56(+) leukaemia' or 'leukaemia of plasmacytoid dendritic cell lineage' has a poor prognostic and may lead to include haematopoietic stem cell transplantation in the treatment strategy as early as possible.

REPORT OF CASES

We report here four cases presenting with skin lesions and haematological signs. One of the patients underwent allogeneic stem cell transplantation, with a relapse-free survival of 40 months. We discuss the diagnosis features as well as the treatment options.

CONCLUSION

A collaborative work between dermatologists and onco-haematologists is essential to give patients the best chance of complete and long-term response.