a 27-year - old gentleman presented to the dermatology department with high - grade fever of 3 months and generalized asymptomatic skin lesions of one and a half months duration . he also had knee joint arthritis , bleeding from the gums , hoarseness of voice and significant weight loss . on examination , he was febrile , had enlarged cervical , axillary and inguinal nodes upto 1.5 cm in size and symmetrical arthritis of the knee joints . cutaneous examination revealed multiple infiltrated monomorphic skin - colored papules and nodules [ figure 1 ] over scalp , face , trunk and extremities . he had infiltration of the lid margins , gingival hyperplasia and a mucosal nodule at the anterior pillar of left tonsillar fossa . biopsies from a cutaneous nodule [ figures 2 and 3 ] and an axillary lymph node were obtained . infiltrated papules and nodules over the trunk pandermal infiltrates of atypical cells , ( h and e , original magnification 100 ) atypical blastic appearing cells , ( h and e , original magnification 400 ) histopathology of the cutaneous nodules showed diffuse infiltration of the dermis and subcutis by a tumour composed of medium to large cells with round to ovoid nuclei with fine chromatin , few with visible nucleoli , increased mitosis and scanty to moderate amounts of eosinophilic cytoplasm . tumor cells were positive for cd4 , cd56 [ figure 4 ] and negative for cd8 , cd68 , cd30 , terminal deoxynucleotidyl transferase ( tdt ) , alk-1 and myeloperoxidase ( mpo ) . histopathology of the excised axillary lymph node showed effacement of architecture due to diffuse infiltrate of large sized cells with scanty to moderate amounts of cytoplasm , round to oval or irregularly contoured vesicular nuclei with prominent nucleoli and increased mitosis . histopathology of the cutaneous nodules showed diffuse infiltration of the dermis and subcutis by a tumour composed of medium to large cells with round to ovoid nuclei with fine chromatin , few with visible nucleoli , increased mitosis and scanty to moderate amounts of eosinophilic cytoplasm . tumor cells were positive for cd4 , cd56 [ figure 4 ] and negative for cd8 , cd68 , cd30 , terminal deoxynucleotidyl transferase ( tdt ) , alk-1 and myeloperoxidase ( mpo ) . histopathology of the excised axillary lymph node showed effacement of architecture due to diffuse infiltrate of large sized cells with scanty to moderate amounts of cytoplasm , round to oval or irregularly contoured vesicular nuclei with prominent nucleoli and increased mitosis . histopathology of the cutaneous nodules showed diffuse infiltration of the dermis and subcutis by a tumour composed of medium to large cells with round to ovoid nuclei with fine chromatin , few with visible nucleoli , increased mitosis and scanty to moderate amounts of eosinophilic cytoplasm . tumor cells were positive for cd4 , cd56 [ figure 4 ] and negative for cd8 , cd68 , cd30 , terminal deoxynucleotidyl transferase ( tdt ) , alk-1 and myeloperoxidase ( mpo ) . histopathology of the excised axillary lymph node showed effacement of architecture due to diffuse infiltrate of large sized cells with scanty to moderate amounts of cytoplasm , round to oval or irregularly contoured vesicular nuclei with prominent nucleoli and increased mitosis . the clinical differential diagnoses considered in this patient were cutaneous t - cell lymphoma , cutaneous infiltrates of a myelomonocytic variant of myeloid leukemia , extranodal nk / t - cell lymphoma , sweets syndrome associated with a myeloproliferative disorder and a lepromatous hansen 's disease in type 2 reaction . the diagnosis of cd4 cd56 + hematodermic neoplasm ( blastic plasmacytoid dendritic cell neoplasm ) was made based on the histopathology and immunohistochemistry findings . the tumor cells of blastic plasmacytoid dendritic cell neoplasm have blastoid morphology resembling lymphoblasts or myeloblasts histologically and they are positive for cd4 and cd56 , and in some cases for tdt , but do not express mpo or surface cd3 . since lymphoblastic and myeloblastic neoplasms can also be positive for cd56 , cd4 and tdt , stains for cd3 and mpo should always be performed in order to exclude these entities . similarities exists between cd56 + myeloid leukemia and cd4 cd56 + hematodermic neoplasm in histology and immunophenotype ; however , presence of cd33 , mpo and lysozyme is used to diagnose myelomonocytic myeloid leukemia . the distinctive features of extranodal nk / t - cell lymphoma is the presence of angiotropism and necrosis , cd4 negativity and an association with epstein - barr virus . according to the who / eortc classification cd4/cd56 + hematodermic neoplasm is placed under precursor hematological neoplasm and renamed by who as blastic plasmacytoid dendritic cell neoplasm . this entity was also known as blastic nk cell lymphoma , agranular cd4 natural killer cell leukemia and agranular cd4/cd56 + hematodermic neoplasm . cutaneous disease may be the first detected manifestation of systemic disease in blood , bone marrow , lymph node and other organs including the central nervous system . while localized disease responds well to chemotherapy with radiotherapy , the prognosis of blastic plasmacytoid dendritic cell neoplasm is poor . studies revealed that the patients treated with allogenic or autologous stem cell transplantation had a significantly better prognosis than those treated with only chemotherapy and radiation therapy . blastic plasmacytoid dendritic cell neoplasm is a rare neoplasm constituting 0.7% of cutaneous lymphomasinfiltrated purple - colored papules and nodules are the characteristic skin lesionprognosis of blastic plasmacytoid dendritic cell neoplasm is poor . blastic plasmacytoid dendritic cell neoplasm is a rare neoplasm constituting 0.7% of cutaneous lymphomas infiltrated purple - colored papules and nodules are the characteristic skin lesion prognosis of blastic plasmacytoid dendritic cell neoplasm is poor . blastic plasmacytoid dendritic cell neoplasm is a rare neoplasm constituting 0.7% of cutaneous lymphomasinfiltrated purple - colored papules and nodules are blastic plasmacytoid dendritic cell neoplasm is a rare neoplasm constituting 0.7% of cutaneous lymphomas infiltrated purple - colored papules and nodules are the characteristic skin lesion prognosis of blastic plasmacytoid dendritic cell neoplasm is poor . blastic plasmacytoid dendritic cell neoplasm is a rare neoplasm constituting 0.7% of cutaneous lymphomasinfiltrated purple - colored papules and nodules are blastic plasmacytoid dendritic cell neoplasm is a rare neoplasm constituting 0.7% of cutaneous lymphomas infiltrated purple - colored papules and nodules are the characteristic skin lesion prognosis of blastic plasmacytoid dendritic cell neoplasm is poor .
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 22 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 .