follicular lymphoma

Follicular lymphoma is the most common subtype of non-Hodgkin lymphoma (NHL)

Epidemiology

Estimated to account for ~45% of all NHL cases . Higher rates in North America and Europe .

Pathology

Nodal effacement by closely packed follicles containing small cleaved cells without nucleoli (centrocytes) and larger non-cleaved cells with moderate cytoplasm, open chromatin and multiple nucleoli (centroblasts).

Follicular lymphoma is categorized into grades according to the number of centroblasts per high-power fields (HPF) as follows:

grade 1: 0-5 centroblasts per HPF
grade 2: 6-15 centroblasts per HPF
grade 3: >15 centroblasts per HPF

Markers

CD10: positive
CD5: negative
CD20: positive

Genetics

Translocation t(14;18) is found in the majority of patients with follicular lymphoma.

Treatment and prognosis

It is often indolent yet incurable with a high prevalence of residual mass post-treatment .

Complications

Transformation to a more aggressive type of NHL.