Children are not naturally predisposed to describe what's bothering them so it's important for parents and loved ones of children to be vigilant about watching for lymphoma symptoms in children. There are a handful of lymphoma subtypes that appear more frequently in children, such as Burkitt's lymphoma, one of the most aggressive cancers known to modern medicine (but rare in the West), while pediatric Hodgkin's lymphoma is rare—but not entirely uncommon-in children.
Both of these examples are treatable and even curable despite their aggressive clinical course, but the important thing is to catch them early.
Keep in mind that these are non-specific symptoms and can be indicative of many things, major and minor. Nonetheless, these symptoms should be reported to one's pediatrician or health care professionals as soon as possible so other illnesses can be ruled out.