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Kaposi sarcoma-associated herpesvirus (KSHV), also known as human herpesvirus 8 (HHV8), is a recent addition to the list of human viruses that are directly associated with lymphoproliferative disorders. KSHV was first shown to be involved in multicentric Castleman disease and primary effusion lymphoma (PEL). Subsequently, the virus was identified in solid lymphomas, often of extranodal sites, with morphological and immunophenotypic characteristics similar to those of PEL, and in other lymphoproliferative disorders with heterogeneous clinicopathological presentations. The recent advances in our understanding of the histology, immunophenotype and pathogenesis of these KSHV-associated lymphoproliferative disorders are reviewed. [ABSTRACT FROM AUTHOR]

The article presents information on the presence of mucosa associated lymphoid tissue (MALT) lymphomas in the stomach and its treatment. A low grade gastric MALT lymphoma appears as a diffuse spread of neoplastic cells from the marginal zone of lymphoid follicles. Histological diagnosis can be very difficult if lymphoid follicles are surrounded by diffusely infiltrating small lymphocytes. Approximately 60% of gastric lymphomas are high grade and are termed as diffuse large B cell lymphomas. Effective H pylon treatment can be very effective in achieving an early response. H pylon treatment is recommended in order to avoid the emergence of antibiotic resistant strains which can be hard to eradicate.

A letter to the editor is presented in response to an article related to gastric mucosa associated lymphoid tissue lymphomas that do not respond to Hpylori eradication, which was published in a previous issue.

Objective An aberrant immunophenotype and monoclonality of intraepithelial lymphocytes (IELs) are frequently found in refractory coeliac disease (RCD). However, the utility of continual monitoring of IEL immunophenotype and clonality in the surveillance of RCD remains to be studied. Design The diagnostic and follow-up biopsies from 33 patients with CD, 7 with suspected RCD, 41 with RCD and 20 with enteropathy-associated T cell lymphoma (EATL) (including 11 evolved from RCD) were investigated by CD3ϵ/CD8 double immunohistochemistry and PCR-based clonality analysis of the rearranged T cell receptor (TCR) genes. Results An aberrant immunophenotype (CD3ϵ+CD8- IELs ≥40%) and monoclonality were detected occasionally in CD biopsies, either transiently in patients with CD not compliant with a gluten-free diet or in those who subsequently developed suspected RCD, RCD or EATL. In contrast, the aberrant immunophenotype and monoclonality were found in 30 of 41 (73%) and 24 of 37 (65%) biopsies, respectively, at the time of RCD diagnosis. Among the patients with RCD who did not show these abnormalities in their diagnostic biopsies, 8 of 10 (80%) and 5 of 11 (45%) cases gained an aberrant immunophenotype and monoclonality, respectively, during follow-up. Irrespective of whether detected in diagnostic or follow-up biopsies, persistence of both abnormalities was characteristic of RCD. Importantly, the presence of concurrent persistent monoclonality and aberrant immunophenotype, especially ≥80% CD3ϵ+CD8- IELs, was a strong predictor of EATL development in patients with RCD (p=0.001). Conclusions Continual monitoring of both immunophenotype and clonality of IELs is more important than snapshot analysis for RCD diagnosis and follow-up, and could provide a useful tool for surveillance of patients at risk of EATL. [ABSTRACT FROM AUTHOR]

Aims: Clonality analysis using polymerase chain reaction (PCR) amplification of the immunoglobulin heavy chain (IgH) gene is an important aid to the diagnosis of B cell lymphoproliferative diseases. However, the method has a relatively high false negative rote. In an attempt to improve detection rates simple PCR strategies for clonality andlysis of B cell populations using amplification of Ig light chain genes have been developed. Methods: Novel PCR protocols, designed to amplify Igλ and lgA light chain genes, were evaluated using high molecular weight DNA samples from 28 selected cases of B cell lymphoma with known light chain expression and 12 reactive lymphoid specimens. Products were run on 10% polyacrylamide minigels using heteroduplex analysis. Conventional lgH PCR analysis was also performed. Twelve randomly selected formalin fixed, paraffin wax processed samples from cases submitted for molecular genetic analysis were also studied. Results: Polyclonal products were seen in all reactive lymphoid samples. Using 19K PCR, 24 of 28 lymphomas, including four of five lgH negative cases, displayed monoclonal patterns. Using lgλ PCR, eight of 12 lgλ expressing tumours, including two of five IgH negative cases, showed monoclonal patterns. Standard IgH PCR demonstrated monoclonality in 23 of 28 B cell lymphomas. The detection rate was improved to 27 of 28 lymphomas using heavy and light chain PCR. Efficient amplification was achieved using paraffin wax processed samples, seven of which showed monoclonality compared with eight using IgH PCR. Conclusions: lg light chain PCR, used in conjunction with heavy chain analysis, enables improved detection of B cell monoclonality using routine histological specimens and can provide additional clone specific markers for the study of the biology of B cell tumours. [ABSTRACT FROM AUTHOR]