Histologic features of FL in children and young adults (cohort 1). All cases showed at least partial architectural effacement by a follicular proliferation. In 1 representative case, there are large, expansile, and coalescent follicles (A) composed of small- to medium-sized centrocytes and numerous medium- to large-sized centroblasts (B), consistent with histologic grade 3A (B). In a second case (C), medium-sized centrocytes predominate and centroblasts are uncommon. The neoplastic infiltrate of a third case is composed of relatively small follicles (D), composed predominantly of small centrocytes (E). “Starry-sky” appearance, as illustrated in a fourth case (F), was frequent. Images were captured at ×40 magnification (A,D); at ×100 magnification (F); and at ×400 magnification (B,C,E) with the use of an Olympus, BX53 microscope, Olympus DP25 digital camera.