FIGURE 35–1. Anatomy of nasopharynx (sagittal).
• Inferior: soft palate (free edge)
• Superior/posterior: skull base, clivus, C1
• Roof
• Lateral walls
• Posterior pharyngeal wall
• Details bony/skull base involvement, destruction, erosion
• Better for evaluation of soft tissue, nerves/perineural involvement
• Helpful for evaluation of vascular lesions (see Juvenile Nasopharyngeal Angiofibroma below)
• As in other head and neck sites, may be useful for differentiating between benign and malignant processes
• Can be particularly helpful in follow-up/post-treatment surveillance for NPC
• Evaluation of distant metastases/staging in malignant disease
• May be useful for differentiating between NPC recurrence versus post-radiation changes
PRESENTING SIGNS AND SYMPTOMS OF NASOPHARYNGEAL LESIONS
• Nasal
1. Epistaxis (vascular lesions, malignancies)
2. Nasal obstruction
• Neurologic
1. Cranial neuropathies
FIGURE 35–2. MR (left panels) of a right-sided nasopharyngeal adenocarcinoma, with corresponding PET-CT imaging (right panels) demonstrating FDG avidity of lesion.
• Otologic
1. Hearing loss (mass effect on Eustachian tube leading to middle ear effusion)
2. Otalgia
• Neck mass (NPC)
• In addition to nasopharyngoscopy (Figure 35–3), make sure to do a full head and neck exam including cranial nerve exam, neck exam, otologic exam
1. Consider FNA of enlarged cervical lymph nodes
• Imaging (see above)
• Dental evaluation (if radiation planned)
• Audiometry
• Tornwaldt Cyst
1. Notochord remnant
2. Midline nasopharyngeal cyst
3. Submucosal
4. If symptomatic can consider removal/marsupialization
5. If asymptomatic can observe
– Often discovered incidentally on imaging
– Benign-appearing on imaging
a. Well demarcated
• Mucous retention cyst
• Papilloma
• Vascular lesions
1. Hemangiopericytoma (considered low-grade/malignant)
2. Juvenile nasopharyngeal angiofibroma
– Nasopharyngeal origin
– Signs/symptoms: intermittent epistaxis, nasopharyngeal mass, nasal obstruction
– Males, adolescents
– Traditionally one-third recur; no evidence that this is related to choice of approach
– Locally destructive, can extend as noted below:
a. Posteriorly/superiorly: sphenoid sinus, clivus, skull base, intracranial
b. Anteriorly: nasal cavity, ethmoid sinuses
c. Laterally: pterygopalatine fossa (expansion on imaging; can bow posterior wall of maxillary sinus—Holman-Miller sign on CT)
– Management
a. Preoperative embolization (onyx) has largely become standard of care
■ Can be transarterial versus direct puncture
■ Decreased intraoperative bleeding
■ Decreased operative times
b. Open approaches (transfacial, midface degloving)
■ Advanced lesions
■ In centers where there is not expertise with minimally invasive approaches
c. Endoscopic Resection
■ Has become standard of care at most tertiary centers when feasible
• Rathke’s Cyst
1. Midline
2. Nasopharyngeal epithelium invagination developing into adenohypophysis (anterior pituitary gland)
3. Failure of this pouch to obliterate results in cyst.
4. Cyst can enlarge, cause endocrine dysfunction, involve optic chiasm.
5. High recurrence rate (12.5%)
6. Less endocrine dysfunction with endoscopic (10%) versus microscopic (25%) resection
• Craniopharyngioma
1. Tumor from Rathke’s pouch
2. Can present along course of migration of adenohypopohysis
– From third ventricle to nasopharynx
• Clival lesions
1. Discussed in Chapter 40
2. These can include hematologic malignancies, including plasmacytomas.
3. Malignant lesions (chordoma, chondrosarcoma) are more common than benign ones.
4. The clivus separates the nasopharynx/sphenoid sinus from the retroclival structures (posterior fossa, basilar artery, brain stem).
• Minor salivary gland tumors
1. There are minor salivary glands in the nasopharynx.
– Most commonly pleomorphic adenoma; nasopharynx: uncommon location
• Teratoma
• Congenital Masses
1. Masses more frequently originate in sinonasal locations, but these can include dermoid cysts, gliomas, encephaloceles.
• Nasopharyngeal carcinoma (see section below)
• Adenocarcinoma
• Salivary gland malignancies
1. Adenoid cystic carcinoma (most common)
– Perineural spread
a. MRI more sensitive for detection
b. Survival rates not stabilized after 5 years
■ Lung metastases many years after initial presentation/management
2. Mucoepidermoid carcinoma
• Clival lesions
1. Chordoma
– Most common clival lesion
– Histologically derived from notochord remnants
– Chordoma can present with CN VI palsy as it is next to Dorello’s canal.
– Five-year survival ~65%
– Metastasis very uncommon
2. Chondrosarcoma (second most common)
– Second most common clival lesion
– Derived from endochondral cartilage
– Possible association with Paget’s disease
– Five-year survival rate ~90%
3. Metastasis
– On T2 MRI usually has lower signal compared to chordoma/chondrosarcoma
4. Endoscopic endonasal approaches have evolved considerably, and are now utilized at leading skull base centers.
– Vidian nerve is an important structure to identify, facilitates staying below the ICA intraoperatively.
• Lymphoma
1. Presenting S/Sx
– Neck mass (42%)
– Nasal obstruction (37%)
– Hearing loss (32%)
2. Non-Hodgkin’s more common
3. Burkitt’s lymphoma associated with EBV
– Association between NPC and EBV (see below)
• Usually originates from fossa of Rosenmüller
• Can spread laterally by eustachian tube, involving parapharyngeal space, skull base (foramen ovale)
1. Trotter syndrome
– Unilateral soft palate akinesia
– Unilateral trigeminal neuralgia
• S/Sx
1. Neck Mass (41%)
– Level V in more than half of patients
– Level II (49% of patients with neck mass)
2. Hearing loss/drainage (27%)
3. Nasal complaints (21%)
4. Cranial neuropathies (8%)
– CN VI most commonly
• Staging (Table 35–1)
1. Multiple staging systems in use
– AJCC
a. Relative 5-year survival rates with treatment (www.cancer.org)
TABLE 35–1. Staging and Classification of Nasopharyngeal Carcinoma
Note: WHO = World Health Organization; AJCC = American Joint Committee on Cancer Classifications
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