Blastic Plasmacytoid Dendritic Cell Neoplasm2Cases Report And Literature Review

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is anextremely rare hematopoietic malignancy with a highly aggressiveclinical behavior and a dismal prognosis. It tends to involve multiple sites,with a predilection for skin, followed by lymph nodes, bone marrow andperipheral blood. The diagnosis of BPDCN relies on characteristichistopathology and immunohistochemical features. It is difficult todiagnose due to the overlap of immunophenotypic features with othercancers. On account of the rarity and only recent recognition of thedisease, the standardized therapeutic approach has not been established.In the earlier stage of the disease, chemotherapy can achieve completeremission, but most patients relapse soon. Some studies have shown thatstem cell transplantation can achieve long-lasting remission.Objective：Aimed to analyze the clinical manifestations, histological changes,Immunohistochemical changes of BPDCN to provide furtherclinical basis for correct diagnosis and differential diagnosis.Methods:Comprehensively analyzed the clinical manifestations, histologicalfeatures, immunohistochemical features of2cases of BPDCN andreviewed related literatures.Results:Clinical characteristics showed the predilection for skin. The skinlesions were usually presented as solitary or multiple, purple red orviolaceous, plaques or nodules. There was no obvious self-conscious symptoms except for occasional itch and pain. The involvements oflymph nodes, bone marrow and peripheral blood could also be showed.Histopathological changes revealed a dense monomorphous, non-epidermotropic infiltration of medium-sized blast cells with irregularnuclei in the dermis and hypodermis, separated from the normalepidermis by an uninvolved zone(grenz zone), without angioinvasion orcoagulative necrosis. Immunohistochemical characteristics showed thattumour cells were positive for CD4, CD56, CD123, CD31, CD43, andnegative for CD3, CD20, CD34, CD117, MPO, EBER. The disease had ahighly aggressive clinical behavior and a dismal prognosis.Conclusions:BPDCN occured most frequently in the elderly without racial orethnic differences. It showed a predilection for skin, followed by lymphnodes, bone marrow and peripheral blood. Histopathological changesrevealed a dense monomorphous, non-epidermotropic infiltration ofmedium-sized blast cells with irregular nuclei in the dermis andhypodermis, with a grenz zone between dermis and epidermal layer.Immunohistochemical features showed the expression of CD4, CD31,CD56, CD123, and the lack of CD3, CD20, CD117, MPO, EBER.