Pediatric follicular lymphoma: A report of the first 3 cases from Taiwan and literature review

Follicular lymphoma (FL) is a common lymphoma entity in adults but is rare in children. As opposed to adult cases, pediatric FL is characterized by a high-grade histology, low-stage disease, a lower frequency of both bcl-2 protein expression and BCL2 gene rearrangement, and a more favorable prognosis. During the authors' previous study of pediatric Burkitt lymphoma, they identified 3 cases of pediatric FL. Here the authors present the first series of pediatric FL from Taiwan. The patients were 2 boys and 1 girl, aged from 7 to 14. The presentation sites were cervical lymph node in 2 and tonsil in 1. All cases showed large neoplastic nodules comprising sheets of centroblasts, corresponding to grade 3b FL. Two of the 3 tumors weakly expressed bcl-2 protein. Fluorescence in situ hybridization for IGH, BCL2, BCL6, CCND1, and MYC loci showed that the only chromosomal translocation was rearranged IGH in 1 case. Two patients were at stage I, and 1 at stage III. All were treated with combination chemotherapy and achieved long-term complete remission. Literature review including the current cases showed that 45% cases of pediatric FL expressed bcl-2 protein and 9% cases carried BCL2 gene rearrangement, suggesting an alternate molecular pathogenesis of pediatric FL as compared to their adult counterparts.