Signs in Carotid Body Tumor | Fontaine Sign & Lyre Sign
💎 Buy my Premium ENT Notes
Instant access to 270+ high-yield ENT notes, plus updates during your access period.
🇮🇳 For Indian Students
· To buy all my notes, click here💡 This post is a free outline of my YouTube video. Get my full handwritten notes using the links above.
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.
📝 All topics and questions from this post are explained in detail in my Premium ENT Notes, which are designed for clinical understanding and exam success.
Residency is hard enough. Studying for it shouldn't be 😊
💎 Buy my Premium ENT Notes
Instant access to 270+ high-yield ENT notes, plus updates during your access period.
🇮🇳 For Indian Students
· To buy all my notes, click here