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Juvenile Nasopharyngeal Angiofibroma

Dr Sandeep Singh Awal MBBS MD DNB EDiR DICR FRCR
2022-10-20

15 yr old male presented with recurrent epistaxis with chronic nasal obstructive symptoms.

Observation and interpretation

CECT PNS shows a large mass lesion centered on the left sphenopalatine foramen (green arrow), occupying the nasopharynx, left posterior choana and extending through the pterygomaxillary fissure into the left infratemporal fossa & masticator space . Lesion extends into, and expands the left pterygopalatine fossa and left superior orbital foramen. It causes anterior bowing of the posterior wall of left maxillary sinus leading to decrease in size of left maxillary antrum (orange arrow).
Lesion shows heterogeneous post contrast enhancement with areas of prominent vascularity. Multiple feeders are seen arising from the branches of left external carotid artery.
Bony remodelling with some absorption of adjacent bony walls is evident.
Non-enhancing polypoidal mucosal thickening in left maxillary sinus – Sinustis, secondary to sinonasal obstruction.

Principal Diagnosis

Juvenile Nasopharyngeal Angiofibroma - Stage IIC (Sessions staging)

Differential Diagnosis

This is a classic case!
Imaging differentials to consider include –
- Nasopharyngeal Carcinoma : Bony erosion is more evident. It may cause skull-base erosion or intracranial extension.
- Rhabdomyosarcoma : Usually found in childhood, while JNA is commonly seen in adolescent males. It shows homogenous density isodense to muscle.
- Esthesioneuroblastoma : Also known as Olfactory neuroblastoma, it characteristically shows an avidly enhancing dumbbell-shaped mass with a ‘waist’ at the cribriform plate.

Further Management

ENT referral
Angiography may be beneficial in identifying feeding vessels and for planning presurgical embolization
MRI PNS + Brain for better evaluation of intracranial tumor extension
Presurgical embolization to debulk the tumour
Surgical resection (endoscopic or open)

Teaching Points

Juvenile Nasopharyngeal Angiofibroma (JNA) is a rare, benign highly vascular tumour of the nasopharynx and shows locally agressive behavior. It is usually seen in adolescent males with a history of recurrent epistaxis.
Classical CT imaging findings include an avidly enhancing mass centered on the Sphenopalatine foramen. It expands the Pterygopalatine fossa (green arrow). Gradually, it can extend medially into the nasopharynx and laterally through the Pterygomaxillary fissure into the Infratemporal fossa.
Involvement of the Infratemporal fossa leads to characteristic anterior bowing of the posterior wall of the ipsilateral maxillary sinus (orange arrow). This is known as the ‘Holman-Miller sign’ or the ‘Antral bow sign’.
The classification system based on CT findings proposed by Sessions et al in 1981 is one of the most commonly used staging systems for JNA:
- Stage I
  - IA – Tumour is limited the nasal cavity/nasopharynx, no paranasal extension
  - IB – Tumour involves the nasal cavity/nasopharynx and one or more paranasal sinuses
- Stage II
  - IIA – Minimal extension of the tumour laterally through the sphenopalatine foramen, into the medial portion of the pterygomaxillary fossa
  - IIB – Tumour completely occupies the pterygomaxillary fossa with anterior bowing of the posterior wall of the ipsilateral maxillary sinus or orbital extension through the inferior orbital fissure
  - IIC – Tumour extends through the pterygomaxillary fossa into the infratemporal fossa
- Stage III
  - Intracranial extension of the tumour