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

9 subordinate codes

• 2A80.0Follicular lymphoma grade 1
• 2A80.1Follicular lymphoma grade 2
• 2A80.2Follicular lymphoma grade 3
• 2A80.3Primary cutaneous follicle centre lymphoma
• 2A80.4Paediatric type follicular lymphoma
• 2A80.5Follicular lymphoma in situ
• 2A80.6Follicular lymphoma of small intestine
• 4B4YOther specified diseases of the immune system
• 4B4ZDiseases of the immune system, unspecified

Nearby in Mature B-cell neoplasms

• 2A81Diffuse large B-cell lymphomas
• 2A82Mature B-cell neoplasm with leukaemic behaviour
• 2A83Plasma cell neoplasms
• 2A84Heavy chain diseases or malignant immunoproliferative diseases
• 2A85Other specified mature B-cell neoplasms or lymphoma
• 2A86B-cell lymphoma, mixed features
• 4B4ZDiseases of the immune system, unspecified