Typically the distinction between childhood and adult non-Hodgkin's lymphoma is made around 15 years of age. Lucy, being 15, is on the cusp. She certainly doesn't like to be referred to as a child, so as her big sis, I find the need to call her that constantly.
I decided to look into childhood NHL a little more, and I learned that there are four main types:
1) B-cell non-Hodgkins lymphoma
2) Diffuse large B-cell lymphoma
3) Lymphoblastic lymphoma
4) Anaplastic large cell lymphoma
What a mouth full! Other, less prevalent form of childhood NHL exist too, such as lymphoproliferative disease. The difference between these categories is the way the cell looks under a microscopic.
I forget which kind Lucy has, but now I can sound smart the next time I take her to the hospital and ask her doctor.