Clinical Findings

The tumor typically occurs in males 14 to 25 years of age, although there are reports of it occurring in elderly women.^4,5 The most common initial symptoms are epistaxis and unilateral nasal obstruction. The occurrence of other symptoms is primarily dependent on the direction and extent of regional spread. The tumor may spread to the nasal cavity, paranasal sinuses, orbit, and intracranial cavity. Symptoms may include proptosis, diplopia, pain and swelling in the cheek, headache, sinusitis, and hearing loss. In comparison, extranasopharyngeal angiofibromas are extremely rare; may arise from sites other than the nasopharynx, most commonly the maxilla but also the ethmoid, nasal cavity, and septum; can affect adult women; are less vascular; and usually have local and less aggressive growth.⁶

Neurological examination with particular attention to cranial nerve function is essential. Fiberoptic nasal examination is performed by the ear, nose, and throat physician. JNAs are typically gray-red, smooth, sessile polypoid masses that can also be irregular and lobulated. The nodularity increases with age. The part that is seen in the nasopharynx and is covered by mucous membrane is typically red/pink, whereas parts that have spread to adjacent extrapharyngeal areas are often white or grey. Otoscopic examination may reveal a serous middle ear effusion or retracted tympanic membrane.

Imaging and Histopathology

Historically, the most suggestive finding was the antral or Holman-Miller sign: anterior bowing of the posterior wall of the maxillary sinus observed on a submentovertical plain skull radiograph (Waters view). All patients should undergo computed tomography (CT) and magnetic resonance imaging (MRI). CT is the preferred modality for the initial evaluation because it precisely defines the bony architecture of the sinonasal tract and skull base and outlines the orbital involvement (Fig. 145-1). MRI better defines the soft tissue planes, especially when the tumor extends beyond the nasopharynx into the infratemporal fossa and when intracranial spread has occurred (Fig. 145-2). Two constant features include (1) a mass in the posterior nasal cavity and pterygopalatine fossa and (2) erosion of bone behind the sphenopalatine foramen extending to the upper medial pterygoid plate.⁷ The vascular nature of JNAs is seen by the presence of flow voids on MRI. The tumor avidly enhances, and intracranial extensions may be extradural or intradural. The tumor may spread through paths of least resistance. In general, there are five directions of spread: (1) anteriorly to the nasal cavity and sinuses; (2) posteriorly to the pterygoid fossa; (3) laterally to the pterygopalatine (pterygomaxillary) fossa and infratemporal fossa; (4) superiorly into the sphenoid with possible further erosion through the posterior wall to the cavernous sinus; and (5) medially into the orbit through the inferior orbital fissure, backward toward the orbital apex, extension out through the superior orbital fissure, and extension into the cavernous sinus.

FIGURE 145-1 A and B, Nonenhanced axial CT images showing a mass in the nose and sinuses. Note the location of the mass and the associated bony destruction.

FIGURE 145-2 Nonenhanced (A) and enhanced (B) midsagittal T1-weighted magnetic resonance images showing a brightly contrast-enhancing mass in the nose and sinuses. The tumor is in the nasal airway and sinuses but does not appear to enter the intracranial space.

Diagnostic and interventional angiography is typically performed on these tumors in preparation for surgical excision. The blood supply is usually derived from the external carotid system, in particular, branches from the internal mammary and ascending pharyngeal arteries. Contribution from the internal carotids may occur as the tumor spreads beyond the confines of the nasopharynx and is the rule for intracranial extension. Thus, both the internal and external carotid circulations should be evaluated.

Grossly, this lesion is typically nonpedunculated, well circumscribed, often multilobular, firm and rubbery, and variably pale tan-gray to maroon red (Fig. 145-3A). Focal surface mucosal ulceration is occasionally seen in this otherwise smooth and shiny surfaced lesion. Cut sections are solid to often spongy, depending on vascularity (Fig. 145-3B).

FIGURE 145-3 A, Gross specimen showing the external lobulated and hemorrhagic surfaces of a juvenile angiofibroma. B, Cut gross specimen showing the fibrovascular connective tissue composing the lesion.

Microscopically, nasal angiofibroma is typically thinly encapsulated with a respiratory-type mucosal lining. Underlying this lining is a histologically benign component with relatively low to moderate cellularity (Fig. 145-4A). Its associated fibrovascular collagenous connective tissue stroma is often superficially loose but becomes dense with increasing depth from the surface mucosa. The density, prominence, and size of the irregular, variably thin-walled vascular elements vary somewhat. Vessels have a simple endothelial lining, generally lack elastin and much mural smooth muscle (especially in the central depths of the tumor, but this also holds true for most of the superficial vessels), vary in shape from staghorn to stellate to slit-like, and are occasionally even inconspicuous (secondary to compression by surrounding stroma). Some, especially more superficial vessels, have thicker walls with more smooth muscle and an arteriolar appearance. The vascular component appears to be most prominent during the early growth phase of tumor development. The cytologically innocuous-appearing stromal fibroblasts and occasional myofibroblasts may demonstrate a perivascular proclivity. These cells vary from spindle to ovoid to stellate appearing. Small nucleoli are often seen in these cells. Foci of myxoid or hyalinizing degenerative change may be observed. Mitotic activity is generally rare, infrequent, or inconspicuous. Mast cells are often plentiful, but inflammatory infiltrates are otherwise usually minor, unless the lesion is recurrent or has been subjected to ancillary therapies (Fig. 145-4B). Obviously, this highly consistent and characteristic histopathology may be altered by preoperative embolization therapy; secondary changes such as a foreign body reaction, tumor necrosis, increased inflammation, and increased nuclear atypia may then be observed. Likewise, some such features (i.e., increased inflammation and nuclear atypia) may be more prominent in recurrent lesions.

FIGURE 145-4 A, Photomicrograph (50×) again showing the typical, variably thin-walled blood vessels with variable shapes within a background fibrocollagenous connective tissue stroma. This is from a deeper region of the lesion, which frequently shows greater stromal cell density than do more superficial regions of nasal angiofibroma (NAF). In addition, blood and vessels are more obvious in this particular area because the vessels are congested in this focus. B, Photomicrograph (200×) showing a prominent (at high power) feature typical of nearly all NAF: a generally sparse but rather diffuse inflammatory cell infiltrate composed most prominently (or nearly entirely) of scattered mast cells. Mast cells have a so-called fried-egg appearance, with central round to ovoid nuclei and abundant finely granular basophilic cytoplasm.

Staging

Numerous staging systems based on tumor extent and spread have been proposed and help facilitate decision making regarding surgical approaches and prognosis (Table 145-1).^1,8–11 The Sessions classification was the first, with other authors making modifications to it. For example, Radkowski made a minor change to stage IIC to account for extension posterior to the pterygoid plates in the infratemporal fossa.⁹ Tumors in this location are in close proximity to the foramen lacerum and thus the carotid artery and make complete surgical excision more difficult. Radkowski also differentiated between minimal (IIIA) and extensive (IIIB) intracranial involvement. Önerci and colleagues developed the most recent classification system to take into account improved radiographic imaging, embolization, and surgical methods, particularly endoscopic techniques.¹¹

Management

Histologic confirmation is not usually necessary for the diagnosis; it can be made with sufficient certainty from the clinical picture and radiographic information. However, when tissue is required to make a diagnosis, such as when the diagnosis is in question or in patients who are poor surgical candidates, biopsy should be performed in the operating room under general anesthesia with a controlled airway. The surgeon should be prepared for brisk hemorrhage from the biopsy site. The differential diagnosis includes pyogenic granuloma, choanal polyp, angiomatous polyp, nasopharyngeal cyst, chordoma, and carcinoma.