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Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare and aggressive hematological malignancy characterized by proliferation of plasmacytoid dendritic cell precursors. Herein, we describe a 65-year-old male presented with a 6 month history of a progressively enlarging purple mass over his forehead. The histopathological examination revealed non-epidermotropic, dermal, and subepidermal homogeneous infiltration with moderate-sized cells resembling lymphoblasts or myeloblasts. The neoplastic clone diffusely stained positive with CD4 and CD56. They were negative for CD3, CD20, pax-5, CD30, myeloperoxidase, and TdT. Rearrangement studies for T and B cell receptor were negative. Ki-67 proliferation index was 80%. Involvement of multiple lymph nodes was detected. Bone marrow biopsy was normal. The patient was put on six cycles of R-CHOP chemotherapy which was successfully cleared all lesions. A rapid recurrence was observed after 1.5 months. While being prepared for autologous stem cell transplantation, the patient died due to rapidly onset myelosuppression and systemic infections. In conclusion, BPDCN should be in the clinical and histopathological differential diagnosis of rapidly developing tumoral cutaneous lesions. Early diagnosis is important to initiate aggressive treatments in BPDCN, in which skin involvement is very frequent.

In this study, it is aimed to analyze the quasi-static response of viscoelastic Kirchhoff plates with mixed finite element formulation based on the Gâteaux differential. Although the static response of elastic plate, beam and shell structures is a widely studied topic, there are few studies that exist in the literature pertaining to the analysis of the viscoelastic structural elements especially with complex geometries, loading conditions and constitutive relations. The developed mixed finite element model in transformed Laplace-Carson space has four unknowns as displacement, bending and twisting moments in addition to the dynamic and geometric boundary condition terms. Four-parameter solid model is employed for modelling the viscoelastic behaviour. For transformation of the solutions obtained in the Laplace-Carson domain to the time domain, different numerical inverse transform techniques are employed. The developed solution technique is applied to several quasi-static example problems for the verification of the suggested numerical procedure.