Polycythemia Vera Terminating in Refractory Ascites

A 64-year-old woman,with more than a 20 year history of polycythemia vera(PV),developed portal hypertension,myelofibrosis and extramedullary hematopoiesis accompanied by massive ascites. Portal hypertension resulted not only from infiltration of the liver sinusoids by hematopoietic cells but also from nodular regenerative hyperplasia of the liver. Wright-stained smears of ascites samples consisted of mesothelial cells and macrophages. However,cultures of mononuclear cells from the ascites showed the presence of hematopoietic progenitor cells including megakaryocyte colony formation and burst forming units. The JAK2-V617F mutation was positive in granulocytes. Contrary to other reports, radiation therapy was not effective and severe myelosuppression continued for more than one month. We present the unusual clinical course for this case of PV and discuss the pathophysiology of refractory ascites

Der(2)t(2;11)(p21;q23), a Variant form of t(2;11), in Biphenotypic Acute Leukemia with T Lymphoid Lineage and M yeloid Lineage Differentiation

We describe a patient with biphenotypic acute leukemia (BAL) with T-lymphoid lineage and myeloid lineage differentiation［BAL (T/M)］. Cytogenetic analysis revealed complex chromosomal abnormalities, including der(2)t(2;11)(p21;q23). Neither leukemia cells nor T-cell receptor gene rearrangements were detected in the bone marrow samples after four courses of high dose cytosine arabinoside regimen. However, der(2)t(2;11)(p21;q23) anomaly persisted in most of metaphases. Fluorescence in situ hybridization (FISH)analysis with a probe for MLL did not detect the split signal. Forty-five cases of hematological disorder with t(2;11)(p21;q23) abnormality have been previously reported. The majority of such cases have been classified as myelodysplastic syndrome(MDS) or acute myeloid leukemia (AML). This is the first case BAL (T/M) associated with a t(2;11)(p21;q23) anomaly

Characterization of CD56+ dendritic-like cells: a normal counterpart of blastic plasmacytoid dendritic cell neoplasm?

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare hematological malignancy. Plasmacytoid DCs (pDCs), which are defined as lineage marker (Lin)(-)HLA-DR(+)CD56(-)CD123(+)CD11c(-) cells, are considered to be the normal counterpart of BPDCNs. However, BPDCN can be distinguished from pDCs by uniform expression of CD56. In this study, to identify a normal counterpart of BPDCN, we searched for a Lin(-)HLA-DR(+)CD56(+) population and focused on a minor subpopulation of Lin(-)DR(+)CD56(+)CD123(+)CD11c(-) cells that we designated as pDC-like cells (pDLCs). pDLC constituted 0.03% of peripheral blood mononuclear cells (PBMCs), and the pDLC/pDC ratio was higher in bone marrow cells than in PBMCs. pDLC clearly expressed BDCA2, BDCA4, and myeloid antigens, which are frequently expressed by BPDCN. pDLCs exhibited modest expression of Toll-like receptors and produced less interferon-α after CpG stimulation, but presented very low endocytic ability unlike mDCs. These functional differences were attributed to the expression profile of transcriptional factors. After in vitro culture with Flt3-ligand and GM-CSF, pDLCs expressed CD11c and BDCA1. These data suggested that pDLCs are a distinct subpopulation, with an immunophenotype similar to BPDCNs. Moreover, our results indicate that pDLCs might be immature DCs and might contribute to the immunophenotypical diversity of BPDCNs