Objective: Due to their rarity, the endoscopic features and clinical backgrounds of colorectal follicular lymphoma lesions have not yet been fully investigated. The aim of this study was to reveal the characteristics of this disease entity.
Methods: A database search performed at the Department of Pathology of our institute identified 12 follicular lymphoma patients with involvement in the cecum, colon, and/or rectum. Data regarding the endoscopic, radiological, biological, and pathological examinations performed were retrospectively reviewed from their clinical records.
Results: The mean age of the patients (5 men, 7 women) was 58.7 years. Five patients were classified as being Lugano system stage I, while the other seven patients were stage IV. In all of the patients, colorectal follicular lymphoma presented with papular (n=4), polypoid (n=4), and flat elevated lesions (n=4). No erosions or ulcers were seen in any of the lesions. The initial pathological diagnoses included extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (n=2) and colitis/proctitis with infiltration of inflammatory cells (n=3), in addition to the correct diagnosis of follicular lymphoma (n=7).
Conclusion: Colorectal involvement of follicular lymphoma shows no erosions or ulcers. These lesions could be macroscopically observed as papular, polypoid and flat elevated lesions. Making a correct diagnosis of this disease based on the findings of biopsied samples is sometimes challenging. In such cases, multiple biopsies and/or endoscopic mucosal resection is required, in addition to appropriate consultation with pathologists.