Nasopharyngeal angiofibroma

Nasopharyngeal angiofibroma is a benign, vascular, polypoid fibrous mass in located in the the posterolateral wall of the nasal cavity. It was first described by Hippocrates, a Greek physician, in the 5th century BC. Nasopharyngeal angiofibroma may be classified according to Fisch classification into 4 groups. Nasopharyngeal angiofibroma is a histologically benign tumor. This tumor is located in the posterolateral wall of the nasal cavity. On gross pathology, characteristic findings of nasopharyngeal angiofibroma include tan to purple-red, rubbery-firm unencapsulated polypoid fibrous mass. Fibroblastic cells with plump (near cuboidal) nuclei and abundant capillaries are seen on microscopic histopathological analysis. The cause of Nasopharyngeal angiofibroma has not been identified, but it may be caused by hormonal effect. Incidence of juvenile nasopharyngeal angiofibroma is less than 0.5% of head and neck tumors. If left untreated, %9 of patients with nasopharyngeal angiofibroma may progress to develop hemorrhage and intracranial extension. The hallmark of Nasopharyngeal angiofibroma is the classic triad of epistaxis, unilateral nasal obstruction and a mass in the nasopharynx. Physical examination of patients with Nasopharyngeal angiofibroma is usually remarkable for nasal mass and rhinorrhea. Findings on an x-ray suggestive of nasopharyngeal angiofibroma include nasopharyngeal polyp and Antral sign or Holman-Miller sign (Forward bowing of the posterior wall of the maxillary sinus). CT scan and MRI demonstrate the extent of the tumor. The mainstay of treatment for nasopharyngeal angiofibroma is surgical resection.

• Nasopharyngeal angiofibroma was first described by Hippocrates, a Greek physician, in the 5th century BC.^[1]

• In 1940, Friedberg was the first to use the term angiofibroma.
• The first endoscopic resection of nasopharyngeal angiofibroma was done in 1996.

Nasopharyngeal angiofibroma may be classified according to Fisch classification into 4 groups: ^[2]

• Type I: Sphenopalatine foramen, nasopharynx, and nasal cavity are involved without bone destruction.

• Type II: Nasal sinuses or the pterygomaxillary fossa are involved with bone destruction.
• Type IIIa: Infratemporal fossa or orbit are involved without intracranial involvement.
• Type IIIb: Infratemporal fossa or orbit are involved with intracranial extradural commitment.
• Type IVa: Intracranial extradural and/or intradural are involved, but optic nerve, sella, or cavernous sinus are not involved.
• Type IVb: Intracranial extradural and intradura, optic nerve, sella, and/or cavernous sinus are involved.

• Nasopharyngeal angiofibroma is a histologically benign tumor.

• This tumor is located in the posterolateral wall of the nasal cavity.
• Nasopharyngeal angiofibroma may involve sphenoid sinuses, maxillary, ethmoid, pterygoid plate, orbit, base of the skull and extradural.
• In rare cases, nasopharyngeal angiofibroma may involve pituitary, cavernous sinus and/or optic chiasm and anterior fossa. ^[3]

• Genetic alterations associated with the development of nasopharyngeal angiofibroma include:^[4]

• Overexpression PDGF-B
• Overexpression BFGF
• Deletion of chromosome 17
• Tumor suppressor gene p53
• Overexpression of Her-2/neu oncogene

• On gross pathology, characteristic findings of nasopharyngeal angiofibroma include:
  • Bilobed or dumbbell-shaped with average size 3-5 cm ^[5]
  • Tan to purple-red, rubbery-firm unencapsulated polypoid fibrous mass
  • Bleeding on biopsy
  • Spongy cut surface
  • Sessile or pedunculated tumor

• On microscopic histopathological analysis, characteristic findings of nasopharyngeal angiofibroma include:

• Fibroblastic cells with plump (near cuboidal) nuclei
• Fibrous stroma
• Abundant capillaries
• Multinucleated stromal cells

• The cause of Nasopharyngeal angiofibroma has not been identified, but it may be caused by hormonal effect.^[6]

• Nasopharyngeal angiofibroma express higher levels of vascular endothelial growth factor (VEGF) and hormone receptors.

Nasopharyngeal angiofibroma must be differentiated from other diseases that cause epistaxis, unilateral nasal obstruction, and rhinorrhea, such as:^[7]

• Sinonasal polyp
• Rhinosporidiosis
• Chordoma
• Nasopharyngeal cyst
• Pyogenic granuloma
• Nasopharyngeal carcinoma
• Lymphoma
• Rhabdomyosarcoma
• Adenoid hypertrophy

• Incidence of juvenile nasopharyngeal angiofibroma is less than 0.5% of head and neck tumors. ^[8]
• The incidence of juvenile nasopharyngeal angiofibroma is 0.6 per 100,000 individuals worldwide.^[9]
• Some reports suggest juvenile nasopharyngeal angiofibroma is more common in the Indian subcontinent than in the west.^[10]
• Men are more commonly affected by juvenile nasopharyngeal angiofibroma than women.

Common risk factors in the development of nasopharyngeal angiofibroma include:^[11]

• Familial adenomatous polyposis
• Male gender

• There is insufficient evidence to recommend routine screening for nasopharyngeal angiofibroma.

• If left untreated, %9 of patients with nasopharyngeal angiofibroma may progress to develop hemorrhage and intracranial extension.

• Common complications of nasopharengeal angiofibroma include nasal obstruction and repeated bleeding.^[12]

• In general prognosis of nasopharyngeal angiofibroma is good.

The diagnosis of nasopharyngeal angiofibroma is made when the following findings are met:

• Epistaxis
• Unilateral nasal obstruction
• Mass in the nasopharynx

• The hallmark of Nasopharyngeal angiofibroma is the classic triad of epistaxis, unilateral nasal obstruction and a mass in the nasopharynx.
• The most common symptoms of Nasopharyngeal angiofibroma include nasal obstruction, epistaxis and headache.
• Less common symptoms of Nasopharyngeal angiofibroma include conductive hearing loss, diplopia, proptosis, anosmia, recurrent otitis media and eye pain. ^[13]

• Physical examination of patients with Nasopharyngeal angiofibroma is usually remarkable for nasal mass and rhinorrhea.^[13]
• Rare physical examination include:

• • Orbital mass
  • Proptosis
  • Zygomatic swelling
  • Trismus
  • Decreasing vision

There are no diagnostic laboratory findings associated with nasopharyngeal angiofibroma.

There are no ECG findings associated with nasopharyngeal angiofibroma.

An x-ray may be helpful in the diagnosis of nasopharyngeal angiofibroma. Findings on an x-ray suggestive of nasopharyngeal angiofibroma include:^[14]

• Nasopharyngeal polyp
• Antral sign or Holman-Miller sign: Forward bowing of the posterior wall of the maxillary sinus
• Maxillary sinus opacification
• Bony margin may be eroded

• There are no echocardiography/ultrasound findings associated with nasopharyngeal angiofibroma.

CT scan demonstrate the extent of the tumor. Findings on CT scan suggestive of nasopharengeal angiofibroma include:^[15]

• Extension to the sphenoid sinus
• Erosion of the greater sphenoidal wing
• invasion of the pterygomaxillary and infratemporal fossae

Cronal MRI demonstrate the extent of the tumor especially in intracranial involvement. ^[16]

• Findings on MRI suggestive of nasopharengeal angiofibroma include:^[17]
  • Largely isointense to muscle on T1-weighted images
  • Hyperintense on T2-weighted images
  • Internal signal-void regions
  • Intense enhancement after intravenous (IV) contrast injection

The images below demonstrate findings of nasopharyngeal angiofibroma.

• 
  Nasopharyngeal angiofibroma. Skull base invasionImage courtesy of Professor Peter Anderson DVM PhD and published with permission © PEIR, University of Alabama at Birmingham, Department of Pathology
• 
  MRI (T1): Nasopharyngeal angiofibroma 1/3 Image courtesy of Professor Peter Anderson DVM PhD and published with permission © PEIR, University of Alabama at Birmingham, Department of Pathology
• 
  MRI (T1): Nasopharyngeal angiofibroma Image courtesy of Professor Peter Anderson DVM PhD and published with permission © PEIR, University of Alabama at Birmingham, Department of Pathology
• 
  MRI (T1): Nasopharyngeal angiofibroma 3/3 Image courtesy of Professor Peter Anderson DVM PhD and published with permission © PEIR, University of Alabama at Birmingham, Department of Pathology
• 
  MRI (T1): Nasopharyngeal angiofibroma 3/3 (circled)Image courtesy of Professor Peter Anderson DVM PhD and published with permission © PEIR, University of Alabama at Birmingham, Department of Pathology

DSA (digital subtraction angiography) of carotid artery is helpful in the diagnosis extension of nasopharengeal angiofibroma and feeding vessel.^[18]

Other diagnostic studies for nasopharengeal angiofibroma include nasal endoscopy, which demonstrates hypervascularized large, lobulated mass behind the middle turbinate.^[19][20]

The mainstay of treatment for nasopharyngeal angiofibroma is surgical resection.

• Medical therapies for nasopharyngeal angiofibroma include: ^[21]
  • Hormones (estrogen, testosterone)
  • Radiation therapy
  • Chemotherapy
  • Embolization

Arteriography followed by preoperative embolization and surgical resection is the mainstay of treatment for nasopharyngeal angiofibroma. ^[22]

• Surgical approaches for nasopharyngeal angiofibroma include: ^[23]
  • Transpalatal
  • Transmaxillary
  • Lateral rhinotomy
  • Mid-facial degloving
  • Extended sublabial Denker
  • Le Fort type I osteotomy
  • Endoscopic surgery

There are no established measures for the primary prevention of Nasopharyngeal angiofibroma.

Once diagnosed and successfully treated, patients with nasopharyngeal angiofibroma are followed-up after surgery, and every 6 or 12 months, depending on the clinical progression.

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