Follicular lymphoma with leukemic phase at diagnosis: a series of seven cases and review of the literature.

Follicular lymphoma (FL) is a prevalent type of non-Hodgkin lymphoma in the United States and Europe. Although, FL typically presents with nodal involvement, extranodal sites are less common, and leukemic phase at diagnosis is rare. There is mounting evidence that leukemic presentation portends a worse prognosis in patients with FL. We describe 7 patients with a pathological diagnosis of FL who presented with a leukemic phase. We compared our cases with 24 additional cases reported in the literature. Based on our results, patients who present with leukemic FL tend to have higher risk disease. Leukemic FL also seems to be associated with a worse prognosis; however, larger studies are needed to confirm our findings. A discrepancy with previously reported cases of FL in leukemic phase raises the possibility of differences attributable to geographic regions.