# Follicular and Mantle Cell Lymphoma

> Follicular and mantle cell lymphoma for NEET-PG Medicine compare t(14;18) BCL2 with t(11;14) cyclin D1, indolent and aggressive courses and their management.

- Canonical URL: https://prepelephant.com/topics/neet-pg/medicine/follicular-and-mantle-cell-lymphoma
- Exam / course: NEET-PG · Subject: Medicine
- Publisher: PrepElephant (https://prepelephant.com) — Prepared and reviewed by the PrepElephant Academic Review Team
- First published: 2026-10-15
- Last updated: 2026-10-15
- Reference basis: Harrison's Principles of Internal Medicine; WHO Classification of Haematolymphoid Tumours
- How to cite: "Follicular and Mantle Cell Lymphoma", PrepElephant, https://prepelephant.com/topics/neet-pg/medicine/follicular-and-mantle-cell-lymphoma

## Direct answer

Follicular lymphoma and mantle cell lymphoma are B-cell non-Hodgkin lymphomas separated by their translocations: t(14;18) with BCL2 overexpression in follicular lymphoma, and t(11;14) with cyclin D1 overexpression in mantle cell lymphoma. Follicular lymphoma usually runs an indolent course with painless lymphadenopathy, whereas mantle cell lymphoma tends to behave more aggressively. Correct classification shapes the choice between observation and early therapy.

## What you must remember

- **Follicular translocation:** t(14;18)(q32;q21) places BCL2 beside the immunoglobulin heavy chain locus, and BCL2 overexpression blocks apoptosis.
- **Follicular immunophenotype:** CD10 positive and CD20 positive, with CD5 usually negative.
- **Grading:** follicular lymphoma is graded 1 to 3 by centroblast count, and grade 3B behaves more like diffuse large B-cell lymphoma.
- **Mantle translocation:** t(11;14)(q13;q32) drives cyclin D1 overexpression, and SOX11 positivity supports the diagnosis.
- **Mantle immunophenotype:** CD5 positive, with CD10 and CD23 negative, which separates it from most follicular cases.
- **Course:** follicular lymphoma is indolent with relapses, while mantle cell lymphoma is more aggressive and often involves the gut.
- **Gut disease:** lymphomatous polyposis of the intestine is a characteristic feature of mantle cell lymphoma.
- **Prognosis:** the FLIPI stratifies follicular lymphoma, using age, stage, haemoglobin, nodal sites and lactate dehydrogenase.

## Separating the two by markers and translocation

A 60-year-old man has painless neck nodes for two years, and flow cytometry shows CD5 positivity with CD10 negativity. The immunophenotype points towards the mantle cell side (CLL is also CD5 positive but CD23 positive), and cyclin D1 with t(11;14) confirms the diagnosis. Which marker is positive decides both the entity and the expected course, so the panel must be read in full.

| Feature | Follicular lymphoma | Mantle cell lymphoma |
|---|---|---|
| Translocation | t(14;18) | t(11;14) |
| Overexpressed protein | BCL2 | Cyclin D1 |
| CD5 | Negative | Positive |
| Typical course | Indolent with relapses | More aggressive |
| Gut involvement | Uncommon | Lymphomatous polyposis |

Use CD5, CD10 and the translocation together, since no single marker separates the two in every case. Follicular lymphoma usually means a slower course, but grade and FLIPI-based risk decide the actual plan.

An excisional node biopsy is preferred over fine needle aspiration alone, because the nodal architecture is needed for grading and to exclude reactive hyperplasia. Ki-67 proliferation is typically low in follicular lymphoma and higher in mantle cell lymphoma, which supports the aggressive label.

## Where the exam tries to catch you

Most lost marks come from treating painless lymphadenopathy as one disease, or from misreading the word indolent.

- **Trap:** Diagnosing follicular lymphoma from any painless nodes in an older adult. — **Correct:** CD5 positivity with cyclin D1 points to mantle cell lymphoma, which runs a more aggressive course.
- **Trap:** Believing indolent means curable. — **Correct:** Follicular lymphoma is generally not curable with conventional therapy, and relapses are the expected pattern.
- **Trap:** Using BCL2 as the marker of mantle cell lymphoma. — **Correct:** BCL2 overexpression is the hallmark of follicular lymphoma, while mantle cell lymphoma is defined by cyclin D1.
- **Trap:** Assuming all low-grade follicular lymphoma needs immediate therapy. — **Correct:** Asymptomatic, low-burden disease is often observed, and therapy is reserved for symptoms or high tumour burden.

## Frequently asked questions

### Which translocation is characteristic of follicular lymphoma?

Follicular lymphoma is characterised by the t(14;18)(q32;q21) translocation, which places BCL2 beside the immunoglobulin heavy chain locus. BCL2 overexpression blocks apoptosis, allowing the B-cell clone to accumulate over time.

### How does mantle cell lymphoma differ from follicular lymphoma on immunophenotype?

Mantle cell lymphoma is CD5 positive and CD10 negative, with nuclear cyclin D1 overexpression from t(11;14). Follicular lymphoma is CD10 positive and usually CD5 negative, which separates the two in most cases.

### What is the typical course of follicular lymphoma?

Follicular lymphoma usually follows an indolent course with painless lymphadenopathy that can persist for years. Transformation to diffuse large B-cell lymphoma is the key adverse event and needs prompt reassessment.

### Why is mantle cell lymphoma considered more aggressive than follicular lymphoma?

Mantle cell lymphoma generally behaves more aggressively than follicular lymphoma, with frequent extranodal and gastrointestinal involvement and a shorter course. Lymphomatous polyposis of the gut is a characteristic finding in many patients.

### Which prognostic index is used for follicular lymphoma?

The Follicular Lymphoma International Prognostic Index (FLIPI) stratifies risk in follicular lymphoma. It combines age, stage, haemoglobin, number of nodal sites and serum lactate dehydrogenase to guide treatment decisions.