Newly diagnosed and relapsed follicular lymphoma: ESMO clinical recommendations for diagnosis, treatment and follow-up.

Diagnosis should always be based on a surgical specimen/ excisional lymph node biopsy. Core biopsies should only be performed in patients without easily accessable lymph nodes (e.g. retroperitoneal bulk). Fine needle aspirations are inappropriate for a reliable diagnosis. The histological report should give the diagnosis according to the WHO classification. Grading is performed according to the number of blasts/high-power field (grade 1–2: £15 blasts, grade 3: >15 blasts). Follicular lymphoma grade 3B (with sheets of blasts) is considered an aggressive lymphoma and treated alike (see clinical recommendation DLCL). When possible additional biopsy material should be stored fresh frozen to allow additional molecular (currently still scientific) analyses.