JUVENILE NASOPHARYNGEAL ANGIOFIBROMA

📌 Definition: It is a rare tumour, but the commonest benign tumour of the nasopharynx. It is highly vascular, locally invasive, and non-encapsulated.

Aetiology & Origin

• Age/Sex: Seen almost exclusively in Adolescent Males (10-20 yrs, 2nd decade).
• Cause: Testosterone Dependent (Hamartomatous nidus of vascular tissue activated by puberty).
• Site of Origin: Posterior part of the nasal cavity, near the superior margin of the Sphenopalatine Foramen.

Spread of Tumour

The tumour spreads by three specific modes:

1. Mode A (Least Resistance): Spreads through nose, nasopharynx, and fissures/foramina (e.g., Foramen Rotundum, Vidian Canal, Inferior Orbital Fissure, Palatovaginal Canal).
2. Mode B (Expansion): Pushes structures. Example: Pushing the posterior wall of the Maxillary sinus giving the Holman Miller (Antral) Sign.
3. Mode C (Bone Destruction): Infiltrates and destroys bone (e.g., root of pterygoid, greater wing of sphenoid).

Routes of Extension

Direction	Pathway & Consequences
Anterior	Into Nasal Cavity → Blocks choana (Nasal obstruction).
Posterior	Into Nasopharynx → Epistaxis.
Lateral	Enters Pterygopalatine Fossa → Destroys post. wall of Maxilla → exits Pterygomaxillary fissure → enters Infratemporal Fossa (Cheek Swelling).
Superior/Orbital	Enters Orbit via Inferior Orbital Fissure → Proptosis, Diplopia, Pressure on Optic Nerve.
Intracranial	Via Foramen Rotundum → Middle Cranial Fossa (usually extradural). Can involve Cavernous sinus, Parasellar region, Optic chiasma.

Note on Recurrence: Spread into the Vidian (Pterygoid) canal or Palatovaginal canal may remain hidden and is a common cause of recurrence.

Pathology: Genetics & Growth

Gross & Microscopic Appearance

• Gross: Reddish-purple, lobulated, sessile mass. Covered with mucosa. No Capsule. Firm or soft depending on collagen content.
• Microscopic Components:
  1. Vascular Tissue: Endothelium-lined spaces. LACK muscular and elastic coats (Peripheral capillaries are thin-walled; Central vessels may have incomplete muscle).
  2. Stromal Cells: Stellate or spindle-shaped fibroblasts (produce collagen).

Hormones & Genetics

• Theory of Origin: Malformed blood vessels (Hamartomatous).
• Androgen Receptors: Found in 75% of tumours (Explains male adolescence predilection).
• Beta-Catenin: Found in stromal cell nuclei; role in proliferation.
• C-MYC: A proto-oncogene found in large angiofibromas.
• Growth Factors: VEGF (Vascular) and IGF-II (Insulin-like).
• FAP Association: JNA is seen 24x more frequently in patients with Adenomatous Polyposis of the Colon.

Surgical Pathology Note

(Key concept for surgery):

• The tumour blood vessels LACK a muscular coat AND elastic coat.
• Consequence: The vessels cannot contract (vasoconstrict). If cut, they bleed torrentially. Adrenaline is ineffective.

Clinical Features

The Classic Triad:

1. Epistaxis: Profuse, spontaneous, and recurrent. (Patient is often anaemic).
2. Nasal Obstruction: Progressive; often associated with Denasal Speech (Rhinolalia Clausa).
3. Mass: A reddish-purple, sessile or lobulated mass in the nasopharynx.

Extensions & Signs:

• Frog Face Deformity: Due to spread into the orbit (Proptosis) + widening of nasal bridge.
• Ears: Conductive Deafness / OME due to Eustachian tube obstruction.
• Cheek Swelling: Spread to the Infratemporal fossa.

Investigations

• Contrast CT (CECT): Investigation of choice to see bony extent.
• Holman-Miller Sign: (Also called Antral Sign). Anterior bowing of the posterior wall of the maxillary sinus. Pathognomonic.

• MRI: Best for Intracranial extension (Soft tissue detail).
• Carotid Angiography (DSA):
  • Shows feeding vessels (Usually External Carotid System; Internal Carotid in large tumours).
  • Allows for Pre-operative Embolization (See management).

Differential Diagnosis (DDx)

JNA must be differentiated from:

• Antrochoanal Polyp: (Common in young, but avascular/pale).
• Enlarged Adenoids: (Common cause of obstruction in kids).
• Olfactory Neuroblastoma: (Malignant).
• Rhabdomyosarcoma: (Malignant, rapid growth).
• Lobular Capillary Haemangioma.
• Haemangiopericytoma.

Management (Detailed)

Surgery is the Treatment of Choice. Spontaneous regression is rare; "wait and watch" is NOT recommended for primary tumours.

1. Pre-operative Optimization

• Blood Transfusion: Arrange 2-3 units (Cross-matched).
• Embolization:
  • Done 24-48 hours before surgery.
  • Reduces vascularity and intra-operative bleeding.
  • Note: Surgery must be done within 48h to prevent revascularization from collateral vessels.

2. Surgical Approaches (Selection)

The approach depends on the tumor extentGoal: Complete excision with minimal morbidity.

Tumour Extent	Recommended Approach
A. Nose & Nasopharynx	Endoscopic Approach (Modern Standard) OR Transpalatal Approach.
B. Plus Maxillary Antrum / Pterygopalatine Fossa	Lateral Rhinotomy (with Medial Maxillectomy) OR Le Fort I (Transmaxillary) OR Endoscopic.
C. Plus Infratemporal Fossa / Cheek	Maxillary Swing (Facial Translocation / Wei's Op) OR Extended Lateral Rhinotomy OR Infratemporal Fossa Approach.
D. Plus Intracranial Extension	Combined Approach (Intracranial + Extracranial). (Neurosurgeon assistance required). OR Radiation if inaccessible.
E. Residual or Recurrent Disease (Extracranial)	Observation OR Repeat Surgery OR Radiation (if inaccessible).
F. Intracranial Residual or Recurrent	Stereotactic Radiation (X-knife or Gamma knife).

Notes on Specific Approaches:

• Transpalatal Approach: Used for tumours confined to Nasopharynx. Can be extended to Sardana’s Approach (Transpalatal + Sublabial) for lateral reach.
• Midfacial Degloving: avoids facial scars (sublabial incision).
• Maxillary Swing (Wei's Operation): Entire cheek and maxilla are swung laterally like a door to access the infratemporal fossa.

3. Radiotherapy

Dose: 3000 to 3500 cGy (in 15-18 fractions over 3-3.5 weeks).

Indications:

• Intracranial extension (where surgery is risky/inaccessible).
• Recurrent inoperable tumours.
• Residual disease.

Drawback: Response is slow (takes 1-3 years to regress). Risk of radiation-induced malignancy later in life.

4. Chemotherapy & Hormonal (Adjuncts)

• Chemotherapy: For aggressive, recurrent, or residual lesions.
  Drugs: Doxorubicin, Vincristine, Dacarbazine.
• Hormonal Therapy: (Testosterone dependent).
  Drugs: Flutamide (Androgen blocker) or Diethylstilbestrol. Used historically; limited success in practice.

5. Recurrence

Recurrence rate is up to 35%.

• Management: Revision Surgery → If that fails → Radiotherapy.