Follicular lymphoma

**Definition:** Follicular lymphoma (FL) is a neoplasm composed of follicle centre (germinal centre) B-cells (typically both centrocytes and centroblasts/large transformed cells), which usually has at least a partially follicular pattern. t(14;18) with BCL2 rearrangement is frequently observed. If diffuse areas of any size comprised predominantly or entirely of blastic cells are present in any case of follicular lymphoma, a diagnosis of diffuse large B-cell lymphoma is also made. Lymphomas composed of centro cytes and centroblasts with an entirely diffuse pattern in the sampled tissue may be included in this category.

**Inclusions:** - follicular lymphoma with or without diffuse areas

**Exclusions:** - Mature T-cell or NK-cell neoplasms