Nodal follicular lymphoma without complete follicular dendritic cell networks is related to localized clinical stage.

Follicular lymphoma is the most common low-grade lymphoma and it frequently presents with a systemic disease, often showing advanced clinical stage (III/IV). The lymphoma cells are usually growing associated with follicular dendritic cell (FDC) networks. Abnormal FDC networks have been reported in duodenal follicular lymphoma, in which cases exhibit lower clinical stages than the nodal cases. In the present study, we analyzed the FDC network distribution pattern of 242 nodal follicular lymphomas by immunohistochemistry. Out of the 242 cases, 27 cases (11%) demonstrated an atypical pattern of FDC networks, in which the CD21 staining totally or partially disappeared in the neoplastic follicles. Furthermore, we compared the clinical data of these 27 cases and 58 typical FDC network cases of follicular lymphoma. We found that in the typical cases, 52 out of 58 patients (90%) showed advanced clinical stage (III or IV), whereas 10 of 27 (37%) atypical FDC network cases showed localized clinical stage (I or II) (P < 0.01). In conclusion, nodal follicular lymphoma with total loss or partially disrupted FDC networks therefore show a lower clinical stage.