Abstract
We report here a rare case of blastic plasmacytoid dendritic cell neoplasm (BPDCN). Tumor cells in this case had a weakly stained basophilic cytosol and nucleus with fine nucleoreticulum and plural numbers of nucleoli. However, pseudopodia-shaped cytoplasmic expansions and vacuoles along the cytoplasmic outline, which are specifically seen in BPDCN cells, were not identified. In BPDCN, various patterns of cell morphology are observed. Similarly to the current case, especially in cases showing blastic cells without morphologic features specific to BPDCN cells that are observed in peripheral blood or bone marrow, it is extremely difficult not only to speculate BPDCN but also to perform differential diagnosis with other types of acute leukemia and leukemic changes of lymphomas by May-Giemsa staining. Many cases do not show typical expression patterns of cell surface antigens (CD markers), and the diagnosis cannot be obtained unless plasmacytoid-dendritic-cell-related CD markers such as CD123, which was confirmed in the current case, are examined. Moreover, rearrangements of the T cell receptor and immunoglobulin genes and of the Epstein-Barr virus (EBV)-encoded RNA 1 (EBER-1) should be negative for a rapid and definite diagnosis. BPDCN is rare but the prognosis is extremely poor. The patient described in this report died at 6 months after the diagnosis. To perform therapy at the early stages, it is important that medical technologists must assume that BPDCN is the disease.
