Colorectal follicular lymphoma: A single-center retrospective study

The concept of "duodenal-type follicular lymphoma (FL)" has already been established as a disease entity. On the other hand, because FL that develops in the colorectum is a rare disease, its clinical characteristics, including its treatment and outcome, are poorly understood.

To clarify the characteristic clinical features of colorectal FL.

We identified 5 patients with FL from December 2010 to July 2022 whose colorectal lesions were confirmed by endoscopic biopsy at our hospital and retrospectively examined their clinical features, including endoscopic findings, treatment, and long-term outcomes.

The median age of the patients was 70 years (range 62-74 years, 3 males and 2 females), and 2 patients were considered to have systemic FL lesions. Endoscopic findings revealed elavated lesions in all 5 patients (polypoid 3, flat elavated 1, papular 1). Only 1 patient underwent therapeutic intervention, and 4 patients chose watchful waiting. Except for 1 patient in which the lesion spontaneously regressed, the disease recurred or progressed in 4 patients, 3 of whom eventually achieved near complete remission with the administration of rituximab and bendamustine (± polatuzumab vedotin). The 5 patients in this study were still alive or exhibited long-term survival before death; the survival time ranged from 8-29 years after the onset of lymphoma.

In the present study, colorectal FL progressed slowly, and overall survival was good because it was sensitive to anticancer drugs even after the disease progressed without initial therapeutic intervention.