---
title: "Signs in Carotid Body Tumor | Fontaine Sign & Lyre Sign"
description: "Carotid body tumor signs: Fontaine horizontal mobility and the Lyre imaging appearance, including their anatomical basis, clinical use, and viva points."
source: "The ENT Resident"
author: "Dr. Mausumi Das"
canonical_url: "https://www.theentresident.com/ent-notes-lectures/signs-in-carotid-body-tumor-fontaine-lyre-sign"
categories: ["Signs, Syndromes, Triads, and Compilation Lists in ENT", "Neck"]
video: "https://www.youtube.com/watch?v=4hBePqc3WEU"
image: "https://media.theentresident.com/og-images/signs-in-carotid-body-tumor-fontaine-lyre-sign.png"
---

# Signs in Carotid Body Tumor | Fontaine Sign & Lyre Sign

Carotid body tumor signs: Fontaine horizontal mobility and the Lyre imaging appearance, including their anatomical basis, clinical use, and viva points. Watch the full video lecture on YouTube: https://www.youtube.com/watch?v=4hBePqc3WEU

## Signs in Carotid Body Tumor

Carotid body tumor is a tumor arising from **paraganglionic tissue at the carotid bifurcation**.

Two classical signs are associated with this tumor. In this post, we will discuss:

* Fontaine Sign
* Lyre Sign

---

### Fontaine Sign

#### 📌 Type of Sign

👉 Clinical Sign seen during **palpation of a neck swelling**.

#### 🔍 What is the Sign?

Fontaine Sign refers to a neck swelling that is:

✅ Mobile from side to side (horizontal mobility)

❌ Not mobile up and down (vertical mobility restricted)

Seen in **Carotid Body Tumor**.

> Why does Fontaine Sign occur?

#### 👨‍⚕️ Eponym

Named after Fontaine, who described this characteristic mobility pattern in carotid body tumors.

---

### Lyre Sign

#### 📌 Type of Sign

👉 Radiological Sign seen on **Angiography**.

#### 🔍 What is the Sign?

Lyre Sign refers to **splaying (separation) of the internal and external carotid arteries at the carotid bifurcation**.

Seen in **Carotid Body Tumor**.

#### 🧠 Why Does it Occur?

The tumor arises at the carotid bifurcation

→ Grows between the internal and external carotid arteries

→ **Widening or splaying of the carotid arteries**

#### 🎵 Why is it Called Lyre Sign?

A lyre is a **U-shaped classical string instrument**.

The splayed carotid arteries resemble the shape of **a lyre**, hence the name **Lyre Sign**.

> What is Pseudo Lyre Sign?

---

### ⭐ High Yield Rapid Revision Table

| Sign | Type | Finding | Seen In |
| --- | --- | --- | --- |
| Fontaine Sign | Clinical | Horizontal mobility present, vertical mobility restricted | Carotid Body Tumor |
| Lyre Sign | Radiological | Splaying of internal and external carotid arteries on angiography | Carotid Body Tumor |

---

### 🧠 Viva Pearls

* Carotid body tumor arises from paraganglionic tissue at the carotid bifurcation.
* Fontaine Sign is a clinical sign elicited on palpation of the neck swelling.
* In Fontaine Sign, the tumor is mobile horizontally but not vertically.
* Vertical mobility is restricted as the tumor is anchored between the internal and external carotid arteries.
* Lyre Sign is a radiological sign seen on angiography.
* Lyre Sign is splaying of the internal and external carotid arteries at the carotid bifurcation.
* Carotid body tumor is highly vascular with an intense tumor blush.
* Always assess vascularity and origin of the tumor when carotid splaying is seen.

---

## About This Note

This free ENT note on Signs in Carotid Body Tumor | Fontaine Sign & Lyre Sign was written by Dr. Mausumi Das and is paired with a corresponding video lecture.

Canonical page of this note: https://www.theentresident.com/ent-notes-lectures/signs-in-carotid-body-tumor-fontaine-lyre-sign

When citing or referencing this content, please credit The ENT Resident and link to the canonical page above.

## Related Notes by Category

- Signs, Syndromes, Triads, and Compilation Lists in ENT: https://www.theentresident.com/ent-notes-lectures/category/signs-syndromes-triads-lists-in-ent.md
- Neck: https://www.theentresident.com/ent-notes-lectures/category/neck.md

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