Pediatric-Type Follicular Lymphoma (PTFL)

Abstract

Pediatric-type follicular lymphoma (PTFL), as defined in the recently updated 2016 World Health Organization Classification of Tumors of Hematopoietic and Lymphoid Tissues, is a rare entity of non-Hodgkin’s lymphoma (NHL) in childhood and adolescence accounting for less than 2% of all cases. PTFL is a mature B-cell neoplasm that is usually CD20+ and BCL2- and does not carry components of diffuse large B-cell lymphoma or rearrangements of BCL2, BCL6, IRF4, and IG loci. The most important histopathological differential diagnosis is large B-cell lymphoma with IRF4 rearrangement, which may be clinically indistinguishable from PTFL. PTFL is associated with male gender, adolescent age, normal serum LDH levels, lack of B-symptoms and limited stage I or II disease, mostly involving peripheral lymph nodes in the head and neck region. Treatment outcomes in PTFL seem to be excellent with either complete resection and an observational strategy only, or with risk-adapted B-cell NHL-type chemotherapy resulting in overall survival rates >95%.