Pathogenesis and Pathology of Pediatric Lymphoma

Lymphoma is the third most common pediatric neoplasm. In the United States, there are close to 2000 new lymphoma cases diagnosed in children every year. Common pediatric lymphomas include Hodgkin lymphoma, Burkitt lymphoma, lymphoblastic lymphoma, diffuse large B-cell lymphoma, and anaplastic large cell lymphoma. Advances in understanding the biology of these lymphomas have led to significantly improved therapeutic outcome and made lymphoma one of the most curable pediatric cancers. There are a few newly proposed or revised entities of lymphoma in the most recent WHO classification, which include Burkitt-like lymphoma with 11q aberration, large B-cell lymphoma with IRF4 rearrangement, pediatric type follicular lymphoma and systemic EBV (Epstein-Barr virus) + T-cell lymphoma of childhood. These new entities are relatively common in children and are not well known. They can be a diagnostic challenge to a pathologist who is not familiar with them. This chapter describes common pediatric lymphomas as well as these new WHO entities with the focus on the epidemiology, pathogenesis, and pathology.