Describe juvenile nasopharyngeal angiofibroma.

Nature and Presentation

• The three features that define IT clinically are the patient, the bleeding and the prohibition ON biopsy
• It occurs in males aged 10 to 20 years. A case in a female should prompt karyotyping.
• Its site of origin is the sphenopalatine foramen and the posterolateral wall of the nasal cavity, from which it spreads along natural foramina and fissures rather than by invasion — into the pterygopalatine fossa, the infratemporal fossa, the sphenoid and ethmoid sinuses, the orbit and eventually intracranially
• The HOLMAN-MILLER sign — anterior bowing of the posterior wall of the maxillary sinus — reflects that expansion into the pterygopalatine fossa, and is classical and virtually pathognomonic
• Its blood supply is chiefly from the internal maxillary artery (external carotid), particularly the sphenopalatine branch; with contributions from the ascending pharyngeal and, in large or recurrent tumours, from the internal carotid — which matters greatly for embolisation and for the risk of surgery

Investigation and Management

• Contrast-enhanced CT shows an intensely enhancing mass centred on the sphenopalatine foramen, with widening of the foramen and of the pterygopalatine fossa and the HOLMAN-MILLER sign; and defines the bony erosion and skull base involvement
• MRI shows the soft tissue extent, intracranial and orbital spread, and characteristic flow VOIDS giving a "salt and pepper" appearance
• Angiography defines the feeding vessels and, crucially, whether there is internal carotid supply; and permits embolisation
• Preoperative embolisation 24 to 48 hours before surgery substantially reduces intraoperative blood loss and is now standard practice. Doing it too early allows collaterals to recruit.
• Staging systems (radkowski, FISCH, andrews) are based on extension into the pterygopalatine and infratemporal fossae, the orbit and intracranially, and guide the surgical approach and prognosis
• Surgical excision is the treatment of choice
• Endoscopic excision is now standard for early and intermediate tumours, and increasingly for advanced disease in experienced hands, with less morbidity, no facial scar, no effect on facial growth, and lower blood loss
• Open approaches — midfacial degloving, lateral rhinotomy, transpalatal, and infratemporal fossa approaches — for extensive disease, particularly with significant intracranial or lateral extension
• Prepare properly for blood loss — cross-match adequate blood, secure large-bore access, and involve an experienced anaesthetist; this is not an operation to begin unprepared