Primary Follicular Lymphoma in the Rectum Incidentally Found on Screening Colonoscopy

The gastrointestinal tract is the most common site of extra-nodal non-Hodgkin lymphoma. However, the incidence of primary rectal lymphoma is extremely rare. Among the primary gastrointestinal lymphomas, follicular lymphoma has been described as a rare disease. It is difficult to diagnose rectal lymphoma due to its variable growth patterns and inadequate biopsies. Majority of patients with rectal lymphoma have non-specific symptoms or negative biopsies, often delaying the diagnosis. Our patient is a 62-year-old female. Two sessile and smooth subepithelial lesions with a yellowish normal mucosa were found on a screening colonoscopy. The initial mucosal biopsy finding was chronic inflammation, but we were highly suspicion of malignancy; we performed an endoscopic mucosal resection. Herein, we present a rare case of rectal follicular lymphoma diagnosed by endoscopic mucosal resection with a literature review.