A collaborative nationwide lymphoma study in Lebanon: incidence of various subtypes and analysis of associations with viruses.

Incidence of various Hodgkin (HL) and non-Hodgkin lymphoma (NHL) subtypes and association with viruses in Lebanon are not known. We undertook a nationwide study of 272 patients diagnosed with lymphoma in 2007. HL comprised 32.7 % (n = 89) of cases while NHL represented 67.3 % (n = 183). Consistent with the literature, nodular sclerosis was the most predominant HL subtype (n = 57/89). Among NHL, B-cell NHL represented 88 % (n = 161/183), T-cell NHL 9 % (n = 17/183), whereas in 2.7 % it was not classifiable. The B-cell NHL comprised predominantly diffuse large B-cell lymphoma (46 %) and follicular lymphoma (23 %). 81 cases were reviewed by a panel of pathologists with 87.6 % concordance rate. Serology was negative for hepatitis C in 122 tested cases. HIV was positive in 2 cases. Two adult T-cell leukemia/lymphoma were HTLV-I positive. EBV IgG were positive in 88.5 % of cases. 38 EBV seropositive cases [27 NHL (24 B-cell, 3 T-cell) and 11 HL] were studied for EBV genome expression using EBV-encoded RNA (EBER)-in situ hybridization. EBER expression was positive in 8 (21 %) cases (6 HL, 2 T-cell NHL). The distribution of lymphoma subtypes in Lebanon appears similar to that of Western countries. The high rate of EBV positivity in HL and T-cell lymphoma by EBER deserves further investigation.