Dysregulation of microRNAs in angioimmunoblastic T-cell lymphoma.

Background: Angioimmunoblastic T-cell lymphomas (AITLs) are the second most frequent peripheral T-cell lymphomas in humans worldwide and histomorphologically well characterized. MicroRNAs are a group of small non-coding RNAs that can negatively regulate gene expression on a posttranscriptional level. Their dysregulation has been shown to be of importance in numerous tumour entities.

Prevalence of targetable oncogenic mutations and genomic alterations in Epstein-Barr virus-associated diffuse large B-cell lymphoma of the elderly.

Epstein-Barr virus (EBV)-associated diffuse large B-cell lymphoma (DLBCL) of the elderly constitutes a provisional clinicopathological entity in the current World Health Organization (WHO) classification and its genomic features remain sparsely characterized. We investigated a cohort of 26 cases of untreated de novo EBV-positive DLBCL of the elderly by high-resolution array-based comparative genomic profiling and fluorescence in situ hybridization (FISH). Moreover, we screened for activating mutations affecting nuclear factor (NF)-κB pathway signaling and chromatin remodeling (EZH2, CD79B, CARD11 and MYD88) due to their impact of gene expression signatures and postulated upcoming therapeutic targetability.

BCL6-translocations affect the phenotype of follicular lymphomas only in the absence of t(14;18)IgH/BCL2.

Background: The translocation t(14;18)IgH/BCL2 is the molecular hallmark of follicular lymphomas (FL). A subset of cases harbours translocations involving the BCL6-gene locus. This study aimed to determine the frequency of BCL2- and BCL6-translocations in FL and to identify morphological and immuno-histochemical features with respect to the presence of BCL2- and BCL6-translocations.

Sarcoma of follicular dendritic cells with features of sinus lining cells--a new subtype of reticulum cell sarcoma?

Dendritic cell neoplasms of the World Health Organization classification comprise Langerhans cell histiocytosis, Langerhans cell sarcoma, interdigitating dendritic cell sarcoma, follicular dendritic cell sarcoma, and dendritic cell sarcoma, not otherwise specified. Several studies based on immunohistochemical and ultrastructural analysis tried to further clarify the origin of these neoplasms which are thought to derive from mesenchymal or bone marrow precursors. Lymphatic vessel endothelium hyaluronan receptor-1 (LYVE-1) was recently described as a marker for lymphatic endothelium which is expressed on normal liver blood sinusoid lining cells, spleen endothelium, activated tissue macrophages, blood vessels in the lung, endothelial cells of lymphatic sinuses, and in fibroblastic reticular cells in lymph nodes.

Chromosomal aberrations in angioimmunoblastic T-cell lymphoma and peripheral T-cell lymphoma unspecified: A matrix-based CGH approach.

Angioimmunoblastic T-cell lymphoma (AILT) is a histopathologically well-defined entity. However, despite a number of cytogenetic studies, the genetic basis of this lymphoma entity is not clear. Moreover, there is an overlap to some cases of peripheral T-cell lymphoma unspecified (PTCL-u) in respect to morphological and genetic features.