Follicular lymphoma (FL) is a neoplasm derived from follicular center B cells. The incidence rates of FL are highest in America and Western Europe

but are much lower in Asia and developing countries. FL mainly involves lymph nodes

and the patients usually present with painless enlargement of multiple lymph nodes. FL originating from extranodal sites is common in gastrointestinal tract

soft tissues

breast and ocular adnexa. Most patients have an indolent clinical course with a long survival

however

a subset of patients suffer from relapse or progression over years. We reviewed the prognostic factors of FL

in order to provide some theoretical guidance to clinical treatment.