Angiofibroma
Also called juvenile nasopharyngeal angiofibroma (JNA)
Background
Angiofibroma is a benign nasal cavity tumor that almost exclusively effects adolescent boys. The age range for this disease is 7-19, with onset most commonly occurring in the second decade. It has been reported in women and elderly patients on rare occasions, but women who receive the diagnosis should undergo chromosomal studies or have the diagnosis reevaluated. JNA is the most common benign tumor of the nasopharynx, but has a relatively low incidence (1 in 5,000-60,000 of all ear, nose, throat patients) and accounts for only 0.5% of all head and neck tumors. Though benign, it often acts in a malignant manner by eroding into the surrounding sinuses, orbit, or cranial vault.
Causes
It is not clear what causes angiofibroma, though a number of theories exist. The overwhelming male predominance and usual onset around puberty, along with the fact that some JNAs reduce in size after puberty, all seem to point to the influence of a hormonal imbalance. In the most accepted theory, testosterone stimulates the growth of hamartomatous tissue (an abnormal, extraneous formation of normal tissue) of turbinate cartilage that has been mislocated in the nasopharynx and pterygopalatine fossa. Another theory is that the tumor originates during the development of the cranial bones from embryonic chondrocartilage. Other suggested etiologies include trauma, inflammation, infection, allergy, and heredity.
Symptoms
The most common symptoms are nasal obstruction, epistaxis (nose bleeding) and rhinorrhea (runny nose). Patients may also present with facial deformity including cheek swelling, ptosis (drooping eyelids), proptosis (eye protrusion), and cranial nerve palsies. Hearing loss may result from obstruction of the eustachian-tube, and double vision or blindness may result from pressure on the optic nerves and chiasm due to erosion into the cranial cavity. Rarely, patients with a JNA may suffer anosmia—the loss of the sense of smell.
Diagnosis
On physical exam, a pale, smooth mass can be visible inside the nasopharynx. An MRI or a CT scan of the head and facial bones confirms the clinical diagnosis and shows the extension of the tumor. Because the tumor is composed of blood vessels without a muscular coat, a biopsy could lead to extensive bleeding and is therefore generally not performed.
Treatment
Treatment options include the following:
Surgery: JNAs are most often treated by surgery. An angiogram, which is an imaging test that uses x-rays to view blood vessels that have been injected with a contrasting dye, may be performed prior to surgery to allow for embolization of the tumor. Embolization involves cutting off the blood supply of the tumor and significatly reduces blood loss during surgery.
Juvenile angiofibromas can be directly approached through endoscopic endonasal approach (EEA). This state-of-the-art, minimally invasive surgical procedure uses the nose as a natural corridor to reach these lesions, without any incisions in the face or head.
Radiotherapy: Radiation may be used for patients with tumors that have extended into the cranial cavity, whose tumors can't be safely reached by surgery, or who have resurrent disease.
Chemotherapy: Hormonal flutamide, which blocks testosterone receptors, been shown to effectively reduce tumor size, however its sue is restricted to clinical trials.
Prevention
There is no known way to prevent angiofibroma.