Extranodal malignant lymphoma of the upper aerodigestive tract: prevalence of Epstien-Barr virus (EBV) infection in King Chulalongkorn Memorial Hospital.

BACKGROUND: High frequency of Epstein-Barr virus (EBV) in the normal mucosa of the upper aerodigestive tract suggests that it may serve as a reservoir for the virus. Malignant lymphomas arising in this site may be associated with EBV. OBJECTIVES: To determine the prevalence of EBV infection in extranodal malignant lymphomas of the upper aerodigestive tract. SETTING: King Chulalongkorn Memorial Hospital, Thailand. DESIGN: Descriptive study. PATIENTS: 42 Thai patients who presented between 1998 and 2003. MATERIAL AND METHOD: The expression of EBV mRNAs (EBERs) of malignant lymphoma was studied by means of in situ hybridization in formalin-fixed, paraffin-embedded specimens. RESULTS: The recruited subjects were 26 males and 16 females, and their age ranged from 3 to 85 years with the mean of 51.43 years, in 4 of them human immune deficiency virus (HIV) infection was documented. Ten of 42 cases (23.81%) expressed EBER transcripts and were extranodal NK/T-cell lymphomas, nasal type (7 cases), plasmablastic lymphomas (2 cases) and diffuse large B-cell lymphoma (1 case). Three of 4 cases (75%) of known HIV-seropositive cases were EBV-positive (2 plasmablastic lymphomas and 1 diffuse large B-cell lymphoma). CONCLUSION: In the upper aerodigestive tract, EBV was present in some but not all malignant lymphoma. It was associated with extranodal NK/T-cell lymphoma, nasal type and B-cell lymphoma arising in HIV-infected patients, but it was not found in B-cell lymphoma arising in immunocompetent patients.

Extranodal malignant lymphoma of the upperaerodigestive tract in King Chulalongkorn Memorial Hospital according to WHO classification.

BACKGROUND: The Working Formulation commonly used to classify NHL in Thailand has been recognized as imperfect for primary extranodal lymphoma, especially in head and neck regions. OBJECTIVE: To study the clinicopathological and immunohistochemical features of extranodal malignant lymphoma of the upper aerodigestive tract according to WHO classification. SETTING: King Chulalongkorn Memorial Hospital. DESIGN: Descriptive study. PATIENTS: 77 Thai patients who presented between 1998 and 2003. METHODS: Routine histology was performed and stained with H&E and immunohistochemistry, and clinical characteristics were recorded. RESULTS: The patients included 42 males and 35 females, with an average age of 53.87 years. Tumor sites were as follows: Waldeyer ring (n = 42, 54.55%), sinonasal areas (n = 19, 24.67%), oral cavity (n = 9, 11.69%), hypopharynx (n = 4, 5.19%), and larynx (n = 3, 3.90%). Immunohistochemically, 57 tumors (74.02%) were of B-cell phenotype and 19 tumors (24.68%) were of T-cell phenotype. According to the WHO classification, 45 cases (58.43%) were large B-cell, 3 (3.90%) were Burkitt, 3 (3.90%) were marginal zone B-cell lymphomas of mucosa-associated lymphoid tissue (MALT), 4 (5.19%) were follicular lymphoma, 1 (1.30%) was precursor B-lymphoblastic lymphoma, and 1 (1.30%) were mantle cell lymphoma. Among the T-cell lymphomas, 9 (11.69%) were of peripheral T-cell lymphoma, unspecified, 9 (11.69%) were extranodal NK/T cell lymphoma, nasal type, and 1 (1.30%) were anaplastic large-cell lymphomas. In nasal cavity, 8 tumors (42.11%) were extranodal NK/T-cell lymphoma, nasal type, 5 (26.32%) were diffuse large B-cell lymphoma, 4 (21.05%) were peripheral T-cell lymphoma, unclassified, and 1 (5.26%) was Burkitt lymphoma. CONCLUSION: Our data correspond with series from Japan, Hong Kong, and Korea, but there is a significant difference from Western population in T-cell lymphomas of sinonasal area especially extranodal NK/T cell lymphoma of nasal type and peripheral T-cell lymphoma, unspecified which had a higher frequency in Thailand, Japan, Hong Kong, and Korea.