No abstract

Here, we report a retrospective series of 47 EBV-positive diffuse large B-cell lymphoma associated with advanced age. Histopathology allowed to the identification of different histological patterns: cases with polymorphic diffuse large B-cell lymphoma (29 cases), Hodgkin-like (8 cases) and polymorphic lymphoproliferative disorder-like (9 cases) patterns. One case was purely monomorphic diffuse large B-cell lymphoma. We show that this lymphoma type is a neoplasm with prominent classical and alternative nuclear factor-kB pathway activation in neoplastic cells (79% of the cases showed nuclear staining for p105/p50, 74% for p100/p52 and 63% for both proteins), with higher frequency than that observed in a control series of EBV-negative diffuse large B-cell lymphoma (v 2 o0.001). Most cases showed an activated phenotype (95% non-germinal center (Hans algorithm); 78% activated B cell (Choi algorithm)). Clonality testing demonstrated IgH and/or K/Kde/L monoclonal rearrangements in 64% of cases and clonal T-cell populations in 24% of cases. C-MYC (1 case), BCL6 (2 cases) or IgH (3 cases) translocations were detected by FISH in 18% cases. These tumors had a poor overall survival and progression-free survival (the estimated 2-year overall survival was 40±10% and the estimated 2-year progression-free survival was 36±9%). Thus, alternative therapies, based on the tumor biology, need to be tested in patients with EBV-positive diffuse large B-cell lymphoma of the elderly. Modern Pathology (2012) 25, 968-982;

Peripheral nerves consist of 3 layers with differing characteristics: the endoneurium, perineurium, and epineurium. The perineurium represents a continuum with the pia-arachnoid from the central nervous system and extends distally with the sheath of capsular cells of peripheral sensorial organs and propioceptive receptors. It is made of layers of flattened cells surrounded by a basement membrane and collagen fibers, forming concentrically laminated structures around single nerve fascicles. Functionally, the perineurium modulates external stretching forces (that could be potentially harmful for nerve fibers), and along with endoneurial vessels, forms the blood-nerve barrier. Multiple pathologic conditions associated with the perineurium have been described. Perineurial invasion is considered an important prognostic factor in several malignant neoplasms. Perineuriomas are true benign infrequent perineurial cell neoplasms that have been divided in 2 categories: those with intraneural localization and a more common extraneural (soft tissue) group, including sclerosing and reticular variants. Sporadic cases of malignant perineuromas have been reported. Interestingly, neurofibromas and malignant peripheral nerve sheath tumors may also display perineurial cell differentiation. The histologic appearance of perineuriomas may overlap with other soft tissue spindle cell neoplasms. Immunohistochemistry is imperative for the diagnosis, although in certain cases ultrastructural studies may be needed. Typical perineuriomas are positive for epithelial membrane antigen, glucose transporter-1-1, and claudin-1, and negative for S-100 protein and neurofilaments. Perineuriomas have mostly simple karyotypes, with one or few chromosomal rearrangements or numerical changes and it seems that specific cytogenetic aberrations may correlate with perineurioma subtype.

Epstein-Barr virus (EBV)-positive diffuse large B-cell lymphoma of the elderly was included as a provisional entity in the 2008 WHO lymphoma classification. Most reports of this disease come from Asia and little is known about it in other regions of the world, including Latin America. Therefore, in this study, 305 diffuse large B-cell lymphomas in patients above 50 years were analyzed, 136 from Mexico and 169 from Germany. EBV was detected by Epstein-Barr early RNA (EBER) in situ hybridization. Only cases with EBER þ in the majority of tumor cells were regarded as EBV þ diffuse large B-cell lymphoma. The prevalence of EBV þ diffuse large B-cell lymphoma in Mexican patients was found to be 7% (9 of 136), whereas only 2% (4 of 169) of the German cases were positive. The median age at diagnosis was 66 years in the Mexican cohort, as opposed to 77 years in the German group. The site of presentation was in both groups predominantly nodal in nine cases (70%) and extranodal in four cases (30%). Of the 13 EBV þ cases, 10 (77%) were classified as polymorphic and 3 (23%) as monomorphic type. The polymorphic cases showed a non-germinal center B-cell immunophenotype (CD10À MUM1 þ ). Twelve cases (92%) were LMP1 positive and two (15%) expressed EBNA2. An interesting finding was the high frequency of EBV type B with the LMP1 30 bp deletion found in the Mexican cases (50%). Eight of the 11 evaluable cases were B-cell monoclonal by polymerase chain reaction. In summary, we found a similar prevalence of EBV þ diffuse large B-cell lymphoma of the elderly in a Mexican population compared with what has been reported in Asian countries, and in contrast to the low frequency in Western populations (1-3%). However, compared with the Asian series, the Mexican patients were younger at diagnosis, presented predominantly with nodal disease and rarely expressed EBNA2 protein.Modern Pathology (2011Pathology ( ) 24, 1046Pathology ( -1054 doi:10.1038/modpathol.2011 published online 15 April 2011 Keywords: EBV; elderly; large cell lymphoma; Mexico Epstein-Barr virus (EBV) is a ubiquitous herpesvirus that infects 490% of the human population establishing persistent latent infection in the host. 1Although EBV infection is benign in most individuals, it has been linked to the etiology of a rather broad spectrum of B-cell lymphoproliferations both

We report a small, well-demarcated stromal tumor of the gallbladder in a 69-year-old woman. The tumor and associated cholelithiasis led to chronic cholecystitis symptoms. The wall of the gallbladder contained a 2.4-cm hypocellular nodule composed of bland spindle-shaped cells that were immunoreactive for vimentin, CD34, and CD117. With the latter antibody, which stains interstitial cells of Cajal (ICC), the neoplastic cells appear fusiform with elongated bipolar projections or dendritic-like cytoplasmic projections. The gallbladder wall adjacent to the tumor contained numerous CD117-positive cells in close contact with the normal smooth muscle cells, whereas two of 10 gallbladders with minimal chronic cholecystitis showed only a few CD117-positive cells. These findings provide evidence that this stromal tumor of the gallbladder shows ICC differentiation similar to some stromal tumors of the gut. The presence of numerous ICC in the uninvolved gallbladder wall suggests that this tumor might have evolved through hyperplasia of ICC.