An investigation as to whether any association of pediatric HL in Thailand was likely to be EBV positive was performed on formalin-fixed paraffin embedded tissue sections using in situ hybridization for EBV encoded RNA (EBER) technique. The analysis was performed on 15 cases. They were 11 male and 4 female cases. The subtypes of HL according to WHO classification were nodular lymphocyte predominance in 1 (6.6%), nodular sclerosis in 4 (26.6%), mixed cellularity in 9 (60%) and lymphocyte depletion in 1 (6.6%). EBV encoded RNA by in situ hybridization was demonstrated in 92.8% of classic HL: 3 of 4 (75%) with nodular sclerosis; 9 of the 9 with mixed cellularity (100%) and 1 of 1 (100%) with lymphocyte depletion. Case of nodular lymphocyte predominance was negative for EBV, CD 15 CD 30 and positive for CD 20. CD 15 and CD 30 were positive in 78.6% and 85% respectively for classic HL.Our results suggest a strong association of EBV with pediatric classic HL (92.3%) particularly the mixed cellularity subtype (100%). The result confirms the male predominance in pediatric HL. Mixed cellularity is the most common subtype of HL in our series (60%).

Keywords: Epstein-Barr viruses, Hodgkin lymphoma, Pediatric cases, Thailand