B- and T-Lymphocyte distribution in benign and malignant lymphoepithelial lesions of the parotid gland: Correlation with Epstein-Barr virus expression and a proposed mechanism of malignant transformation

Biological and demographic profile of meningiomas in a cohort of Egyptian patients: impact on tumor recurrence

Objective. This work was designed to study the biological and demographic characteristics of meningiomas and their impact on tumor recurrence in Egyptian patients. Material and Methods. A cohort of 265 Egyptian patients with meningioma was studied. Immunohistochemistry for VEGF, Ki67, PR, CD20, and CD3 was performed. Statistical analysis was used to detect independent predictors of recurrence. Results. Adults represented 98.9% of cases, with female preponderance (M : F ratio = 1 : 2.4). Histologically, 78.10% of cases were grade I, 19.20% were grade II, and 2.60% were grade III. Transitional variant was the most common (43.40%). VEGF expression (38.50% of cases) correlated positively with perifocal edema, tumor size, and proliferative index (PI). PR expression (64.5% of cases) correlated inversely with the PI (mean 3.75). Lymphocytic aggregates were detected in 7.20% of cases, with a mean CD20 : CD3 ratio of 1 : 10.1. In a multivariate analysis, only tumor size, PR expression and necrosis predicted recurrence independently. Using ROC curve, size was the best predictor of tumor recurrence with a cut-off point of >6 cm and an excellent negative predictive value (97.6%). Conclusions. Meningiomas in our region showed some distinctive clinicopathological and demographic criteria. Tumor size was found to be the best recurrence predictor factor of meningioma.

Salivary gland and nasopharyngeal cancers in individuals with acquired immunodeficiency syndrome in United States

Individuals with acquired immunodeficiency syndrome (AIDS) manifest an increased risk of cancer, particularly cancers caused by oncogenic viruses. Because some salivary gland and nasopharyngeal cancers are associated with Epstein Barr virus, the impact of AIDS on these cancers needs further evaluation. We used linked U.S. AIDS and cancer registry data (N = 519,934 people with AIDS) to derive standardized incidence ratios (SIRs) comparing risk of salivary gland and nasopharyngeal cancers to the general population. For salivary gland cancers (N = 43 cases), individuals with AIDS had strongly elevated risks for lymphoepithelial carcinoma (SIR 39, 95% CI 16-81) and squamous cell carcinoma (SIR 4.9, 95% CI 2.5-8.6). Among nasopharyngeal cancers (N = 39 cases), risks were elevated for both keratinizing and nonkeratinizing carcinomas (SIR 2.4, 95% CI 1.5-3.7 and SIR 2.4, 95% CI 1.2-4.4, respectively). The elevated risks of salivary gland and nasopharyngeal cancers among people with AIDS suggest that immunosuppression and oncogenic viral infections are etiologically important.

Epstein-Barr virus expression in Hodgkin's disease: Correlation with histologic subtypes and T and B lymphocyte distribution

BACKGROUND

The pathogenesis of Hodgkinâs disease (HD) has been linked to Epstein-Barr virus (EBV). Some histologic subtypes show a high level of viral expression. These include mixed cellularity (MCHD) and nodular sclerosis (NSHD) subtypes. Grade II NSHD is a more aggressive variant of HD. Lymphocyte predominant (LPHD) is a B cell lymphoproliferative disorder that has not been associated with EBV expression. Infiltrating lymphocytes in HD are predominantly T lymphocytes, with a minor component of B lymphocytes. In the current study, EBV expression was tested in cases of HD in relation to histologic subtypes. An attempt was made at correlating EBV expression with T and B lymphocyte distribution in lymph nodes involved by HD.

METHOD

Formalin-fixed paraffin-embedded tissue from 62 cases of HD were tested for EBV mRNA expression, using the EBER-1 probe and in situ hybridization. T and B lymphocyte distribution and their ratios were evaluated using antibodies to T and B lymphocytes (UCHL-1 [CD45 RO] and CD 20, respectively), and the immunoperoxidase technique.

RESULTS

The cases were seen in 38 male and 24 female patients, with an age range of 3 to 72 years (median 25 years). There were 30 cases of grade I and 15 cases of grade II NSHD, 9 cases of MCHD and 8 cases of LPHD. EBV mRNA expression was seen in 29 cases (46%). This expression was seen in 8 cases of grade I NSHD (26%), 13 cases of grade II NSHD (86%) and 8 cases of MCHD (88%). None of the cases of LPHD showed viral expression. T to B lymphocyte ratios in EBV-positive cases ranged from 1/6 to 8/1, and ranged from 2/1 to 20/1 in EBV-negative cases (P=0.06). Nine of the 29 positive cases (31%) showed equal T/B lymphocyte ratios (n=4), or predominance of B lymphocytes (n=5). None of the EBV-negative cases showed predominance of B lymphocytes.

CONCLUSION

Our study confirms previously reported findings of the prevalence of EBV expression in MCHD and NSHD. Our findings also suggest that EBV expression may be more commonly seen in aggressive forms of HD. Decreased numbers of T lymphocytes in these aggressive subtypes may suggest that a process of more profound T lymphocyte depletion is occurring in these cases, leading to uncontrolled EBV replication and more aggressive disease.