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Juvenile Nasopharyngeal

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Juvenile Nasopharyngeal AngiofibromaBackgroundJuvenile angiofibroma (JNA) is a benign tumor that tends to bleed and occurs in the nasopharynx of prepubertal and adolescent males. History of the ProcedureHippocrates described the tumor in the 5th century BC, but Friedberg first used the term angiofibroma in 1940. Other titles (eg, nasopharyngeal fibroma, bleeding fibroma of adolescence, fibroangioma) have also been used.The image below depicts a coronal CT scan.

Coronal CT scan of the lesion filling the left nasal cavity and ethmoid sinuses, blocking the maxillary sinus and deviating the nasal septum to the right side.

EpidemiologyFrequencyJuvenile nasopharyngeal angiofibroma (JNA) accounts for 0.05% of all head and neck tumors. A frequency of 1:5,000-1:60,000 in otolaryngology patients has been reported. SexJuvenile nasopharyngeal angiofibroma (JNA) occurs exclusively in males. Females with juvenile nasopharyngeal angiofibroma (JNA) should undergo genetic testing. AgeOnset is most commonly in the second decade; the range is 7-19 years. Juvenile nasopharyngeal angiofibroma (JNA) is rare in patients older than 25 years. EtiologyThe lesion originates in close proximity to the posterior attachment of the middle turbinate, near the superior border of the sphenopalatine foramen. A hormonal theory has been suggested because of the lesion's occurrence in adolescent males.Other theories include a desmoplastic response of the nasopharyngeal periosteum or the embryonic fibrocartilage between the basiocciput and the basisphenoid. Etiology from nonchromaffin paraganglionic cells of the terminal branches of the maxillary artery has also been suggested. Comparative genomic hybridization analysis of these tumors revealed deletions of chromosome 17, including regions for the tumor suppressor gene p53 as well as the Her-2/neu oncogene.

PathophysiologyThe tumor starts adjacent to the sphenopalatine foramen. Large tumors are frequently bilobed or dumbbell-shaped, with one portion of the tumor filling the nasopharynx and the other portion extending to the pterygopalatine fossa. Anterior growth occurs under the nasopharyngeal mucous membrane, displacing it anteriorly and inferiorly toward the postnasal space. Eventually, the nasal cavity is filled on one side, and the septum deviates to the other side. Superior growth is directed toward the sphenoid sinus, which may also be eroded. The cavernous sinus may become invaded if the tumor advances further. Lateral spread is directed toward the pterygopalatine fossa, bowing the posterior wall of the maxillary sinus. Later, the infratemporal fossa is invaded. Occasionally, the greater wing of the sphenoid may be eroded, exposing the middle fossa dura. Proptosis and optic nerve atrophy result if orbital fissures are encroached upon by the tumor. Extranasopharyngeal angiofibroma is extremely rare and tends to occur in older patients, predominately in females, but the tumor is less vascular and less aggressive than juvenile nasopharyngeal angiofibroma (JNA). PresentationSymptoms Nasal obstruction (80-90%) - Most frequent symptom, especially in initial stages Epistaxis (45-60%) - Mostly unilateral and recurrent; usually severe epistaxis that necessitates medical attention; diagnosis of angiofibroma in adolescent males to be ruled out Headache (25%) - Especially if paranasal sinuses are blocked Facial swelling (10-18%) Other symptoms - Unilateral rhinorrhea, anosmia, hyposmia, rhinolalia, deafness, otalgia, swelling of the palate, deformity of the cheek

Signs Nasal mass (80%) Orbital mass (15%) Proptosis (10-15%) Other signs include serous otitis due to eustachian tube blockage, zygomatic swelling, and trismus that denote spread of the tumor to the infratemporal fossa, decreasing vision due to optic nerve tenting (rare)

Differentials Other causes of nasal obstruction, (eg, nasal polyps, antrochoanal polyp, teratoma, encephalocele, dermoids, inverting papilloma, rhabdomyosarcoma, squamous cell carcinoma) Other causes of epistaxis, systemic or local Other causes of proptosis or orbital swellings

Nasal EndoscopyGiven the presenting symptoms, the patient should be examined by nasal endoscopy which usually shows a large, lobulated mass behind the middle turbinate filling the choana with a smooth surface and clear signs of hypervascularization.

Endoscopic appearance of JA showing a lobulated hypervascularized mass with a smooth surface partially covered by fibrin growing into the left nasal fossa. NS: nasal septum; IT: inferior turbinate; JA: juvenile angiofibroma.Imaging StudiesPlain radiography views of the sinuses may demonstrate nasopharyngeal polyp. Bowing of the posterior wall of the maxillary sinus and maxillary sinus opacification is very suggestive of juvenile nasopharyngeal angiofibroma (JNA). Newer radiographic modalities have surpassed plain films in usefulness. CT scan images below demonstrate the extent of the tumor. Extension to the sphenoid sinus, erosion of the greater sphenoidal wing, or invasion of the pterygomaxillary and infratemporal fossae is usually visualized, as in the images below.

Coronal CT scan of the lesion filling the left nasal cavity and ethmoid sinuses, blocking the maxillary sinus and deviating the nasal septum to the right side. Axial CT scan of lesion involving the right nasal cavity and paranasal sinuses.

Magnetic resonance imaging (MRI) is indicated to delineate and define the extent of the tumor, especially in cases of intracranial involvement. Coronal MRI scan showing extension of the lesion to the cavernous sinus is seen in the image below.

Coronal MRI scan showing extension of the lesion to the cavernous sinus. Angiography shows the branches of the external carotid system to be the primary feeders (94%). The main supply comes from the internal maxillary artery, but ascending pharyngeal or vidian arteries may contribute to the blood supply. Unnamed branches from the internal carotid artery contribute to vascularity in rare instances. Bilateral vascular supply may be an underappreciated factor in JNA, and thorough radiographic investigation via angiography of bilateral carotid systems should be routinely performed preoperatively.[1] An angiofibroma before and after embolization can be seen in the images below.

Angiogram depicting angiofibroma before embolization.

Angiogram depicting angiofibroma after embolization. Histologic FindingsOn gross examination, the tumor is usually sessile, lobulated, rubbery, and red-pink to tan-gray in appearance. In rare cases, the tumor is polypoid or pedunculated. Nasopharyngeal angiofibroma is usually encapsulated and composed of vascular tissue and fibrous stroma with coarse or fine collagen fibers. Vessels are thin-walled, lack elastic fibers, have absent or incomplete smooth muscle, and vary in appearance from stellate or staghorn to barely conspicuous because of stromal compression. Stromal cells have plump nuclei and tend to radiate around the vessels. An abundance of mast cells in the stroma and a lack of other inflammatory cells exist. Localized areas of myxomatous degeneration may be observed in the stroma. When examined under electron microscope, stromal cells are mostly fibroblasts and show intensive immunostaining for vimentin. However, myofibroblasts may occur focally in connection with fibrotic areas and are characterized by the coexpression of vimentin and smooth muscle actin.

(a) (b)

Microscopic appearance of JA (hematoxylin-eosin staining (a) and immunohistochemistry for factor VIII (b)). Vessel caliber is extremely variable, the muscular layer of vessels is frequently absent, and stromal cells have usually a spindle-shaped appearance.

Angiofibroma; Staghorn-shaped blood vessels (arrows) with endothelial cells but no smooth muscle are compressed by fibrous tissue

StagingDifferent staging systems exist for nasopharyngeal angiofibroma. There are many classification described although none is universally accepted. There are a variety of staging criteria developed for evaluating JNAs which include those developed by Radkowski, Fisch, Andrews, Chandler, Johns, Onerci and Sessions although none is universally accepted. In several staging systems that of Andrews (1989) is the most robust and practical for exclusively endoscopic surgery for JNAs17. Another staging system is Radkowski (1996) that is the most recently developed staging system and appears most commonly in recent literature on JNAs. Classification according to Sessions Stage IA - Tumor limited to posterior nares and/or nasopharyngeal vault Stage IB - Tumor involving posterior nares and/or nasopharyngeal vault with involvement of at least 1 paranasal sinus Stage IIA - Minimal lateral extension into pterygomaxillary fossa Stage IIB - Full occupation of pterygomaxillary fossa with or without superior erosion of orbital bones Stage IIIA - Erosion of skull base (ie, middle cranial fossa/pterygoid base); minimal intracranial extension Stage IIIB - Extensive intracranial extension with or without extension into cavernous sinus Classification according to Fisch Stage I - Tumors limited to nasal cavity, nasopharynx with no bony destruction Stage II - Tumors invading pterygomaxillary fossa, paranasal sinuses with bony destruction Stage III - Tumors invading infratemporal fossa, orbit and/or parasellar region remaining lateral to cavernous sinus Stage IV - Tumors invading cavernous sinus, optic chiasmal region, and/or pituitary fossa

Classification according to Andrews Stage I - Limited to the nasopharynx and nasal cavity. Bone destruction negligible or limited to the sphenopalatine foramen Stage II - Invading the pterygopalatine fossa or the maxillary, ethmoid, or sphenoid sinus with bone destruction Stage III(a) Invading the infratemporal fossa or orbital region without intracranial involvement(b) Invading the infr

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