METHODS AND RESULTS: A total of 232 reconfirmed lymphoma cases in Malaysian patients were retrieved from the archives in the Department of Pathology, University Hospital, Kuala Lumpur. There were 24 (10%) Hodgkin's and 208 (90%) non-Hodgkin's lymphomas, 173 of the latter were in adult group (aged > or = 15 years). The ethnic composition were 41 Malays, 107 Chinese, 21 Indians and four none of the above. A male : female ratio of 2.4 : 1 was observed. Complete immunohistochemical studies in 158 cases revealed 36 (23%) T-cell, 121 (76%) B-cell and one (1%) null-cell phenotype. Seventy-five percent of the T-cell lymphomas were peripheral T/NK-cell types. Among the classifiable lesions, low-grade/indolent lymphomas constituted 17%: 2% were the lymphocytic subtype and 10% were follicular lymphomas. Approximately one-third of the follicular lymphomas occurred in Indian patients. The largest group of high-grade lymphoma was diffuse large B-cell type (46%), followed by peripheral T/NK-cell (18%). A predominance of NK/T-cell lymphomas occurred in Chinese (5/7), and all were EBV associated. Burkitt's lymphoma accounted for 5% (eight cases), all were Chinese males, with a 38% EBV-association rate. The frequency of EBV-associated B-cell lymphoma is three times more common in Chinese than Malays. The EBV positivity rate among lymphomas in ethnic Malay, Chinese and Indian patients was 5%, 15% and 22%, respectively, and in T- and B-cell lymphomas was 36% and 7%, respectively.
CONCLUSIONS: This Malaysian series reveals differences in the subtype frequencies of non-Hodgkin's lymphomas and EBV association rate amongst patients of various ethnic groups residing in the same environment.
MATERIALS AND METHODS: This was a descriptive cross-sectional study that included 14 cases of B-cell NHLs of the oral cavity and maxillofacial region. The haematopoietic and lymphoid tissue tumours classification of WHO was used to categorize the cases. In-situ hybridisation for EBV-encoded RNA was performed to confirm the EBV infection.
RESULTS: The average age of the patients included in the study was found to be 48.8 ± 23 years with a higher female to male ratio (1.3:1). Our study suggested that diffuse large B-cell lymphomas (DLBCLs) and Burkitt's lymphomas (BLs) constitute the predominant subtypes of lymphomas affecting the oral cavity and maxillofacial regions.
CONCLUSION: The findings from our study support the view that at least a relatively smaller proportion of B-cell NHLs that occur in the oral cavity and maxillofacial region do not have a pathogenic association with EBV.