• Clinical science

Juvenile nasopharyngeal angiofibroma

Abstract

Juvenile nasopharyngeal angiofibroma (JNA) is a rare, benign, but locally aggressive tumor occurring almost exclusively in adolescent males. JNAs originate from the posterior choanal tissues and rapidly extend into the surrounding regions, including the nasopharynx, the orbits, and even the intracranial cavity. As the tumor is largely space-occupying and highly vascular, patients typically present with a progressive, unilateral nasal obstruction, and recurrent, severe epistaxis. Other symptoms include rhinorrhea, anosmia, and facial swelling (e.g., exophthalmos). The diagnosis is based on the clinical findings and confirmed through cranial CT scans. Surgical excision is the treatment of choice, since JNAs have a high recurrence rate. Radiation (stereotactic gamma knife) is reserved for recurrent cases or JNAs with intracranial extension.

Definition

  • Juvenile nasopharyngeal angiofibroma is a rare, benign, but locally aggressive tumor of the nasopharynx. It is composed of vascular and fibrous tissue.

Epidemiology

  • Incidence: Rare, accounts for 0.05% of all head and neck tumors
  • Sex: occurs exclusively in males
  • Age: 10–20 years

References:[1]

Epidemiological data refers to the US, unless otherwise specified.

Pathophysiology

  • JNAs originate from a hamartomatous nidus in the roof of the nasopharynx
  • JNAs grow rapidly, extending into and distorting adjacent structures (e.g., nasopharynx and nasal cavity, paranasal sinuses, orbit, cranial cavity )
  • The tumor expresses androgen receptors (testosterone dependent); hence, JNAs are seen exclusively in males, especially around puberty, when testosterone levels begin to peak.
  • JNAs have vascular and fibrous components
  • The vessels are devoid of a muscular layer → severe epistaxis

References:[1]

Clinical features

  • The severity of the clinical features depends on the extent of the tumor
  • Progressive unilateral nasal obstruction with septum deviation to the contralateral side (80–90% of cases)
  • Recurrent epistaxis, often torrential , (45–60% of cases)
  • Rhinorrhea, nasal intonation of voice, impaired nasal breathing, anosmia (in very large tumors)
  • Unilateral conductive hearing loss
  • Recurrent headaches due to chronic sinusitis
  • On examination
    • Lobular, pink mass; hard, rubbery texture; bleeds easily on touch
    • Facial swelling

References:[1]

Diagnostics

  • Contrast-enhanced CT scan: Investigation of choice to assess extent of tumor and bone involvement (e.g., invasion into the orbital cavity, paranasal sinuses, fossa infratemporalis)
  • MRI: : Complementary to CT scan to evaluate intracranial extension of the tumor
  • X-ray of paranasal sinuses
    • Opacified sinuses
    • Displaced nasal septum
  • Carotid angiogram: Demonstrates feeding vessels (if preoperative embolization is planned)
  • Biopsy: Recommended only if the diagnosis is uncertain

References:[1][2]

Treatment

  • Surgical excision of the tumor
    • Surgical approach depends on size and extent of the tumor (e.g., transmaxillary, transnasal)
    • Preoperative embolisation of feeding vessels necessary to reduce intra-operative blood loss
  • Stereotactic radiatiotherapy (e.g., gamma knife)
    • Reduces tumor vascularization and size
    • Indicated in recurrent cases; or evidence of intracranial extension
    • Risk of damage to adjacent structures (e.g., eye, brain, spinal cord) is minimised compared to external beam radiotherapy.
  • Hormone therapy with flutamide

References:[1]

Prognosis

  • JNA is known to recur after surgery.
  • Most recurrences occur within four years after surgery and hence, annual/biannual follow-up is required for at least five years.

References:[3]