# Follicular Lymphoma Manifesting as an Isolated Colorectal Polyp‐Like Morphology

**Authors:** Yasuhiko Hamada, Yuhei Umeda, Hayato Nakagawa

PMC · DOI: 10.1002/jgh3.70170 · 2025-04-30

## TL;DR

A rare case of follicular lymphoma in the colon was mistaken for a polyp, showing the difficulty in diagnosing such conditions.

## Contribution

This case report presents an uncommon presentation of primary gastrointestinal follicular lymphoma as an isolated colorectal polyp.

## Key findings

- A 60-year-old woman had a polyp-like lesion in the transverse colon diagnosed as Grade 1 follicular lymphoma.
- The patient also had FL involvement in the proximal jejunum, leading to a stage I diagnosis of primary GI-FL.
- The case emphasizes the diagnostic challenge of distinguishing FL from adenomatous polyps.

## Abstract

Primary gastrointestinal (GI) follicular lymphoma (FL) is a rare entity, and colorectal FL presenting as a solitary polyp is particularly uncommon.

A 60‐year‐old woman presented with hematochezia. Colonoscopy incidentally identified an 8‐mm polyp in the transverse colon, which was subsequently removed via cold snare polypectomy. Histopathological examination confirmed Grade 1 FL, with immunohistochemical analysis revealing positivity for CD10, CD20, and Bcl‐2. Further diagnostic evaluation demonstrated FL involvement in the proximal jejunum, leading to a diagnosis of clinical stage I primary GI‐FL. The patient elected to undergo a watch‐and‐wait approach.

This case highlights the potential for colorectal‐FL lesions to be misidentified as adenomatous polyps, posing a diagnostic challenge.

## Linked entities

- **Proteins:** MME (membrane metalloendopeptidase), MS4A1 (membrane spanning 4-domains A1), BCL2 (BCL2 apoptosis regulator)
- **Diseases:** follicular lymphoma (MONDO:0018906)

## Full-text entities

- **Genes:** MME (membrane metalloendopeptidase) [NCBI Gene 4311] {aka CALLA, CD10, CMT2T, NEP, SCA43, SFE}, KRT20 (keratin 20) [NCBI Gene 54474] {aka CD20, CK-20, CK20, K20, KRT21}, BCL2 (BCL2 apoptosis regulator) [NCBI Gene 596] {aka Bcl-2, PPP1R50}
- **Diseases:** FL (MESH:D008224), I (MESH:D006969), Polyp (MESH:D011127), hematochezia (MESH:D006471), adenomatous polyps (MESH:D018256)
- **Species:** Homo sapiens (human, species) [taxon 9606]

## Figures

1 figure with captions in the complete paper: https://tomesphere.com/paper/PMC12043396/full.md

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Source: https://tomesphere.com/paper/PMC12043396