Nasopharyngeal Carcinoma

NASOPHARYNGEAL CARCINOMA
  • Nasopharyngeal carcinoma is a rare tumor arising from epithelium of the nasopharynx.
  • The most common site of origin for nasopharyngeal carcinoma is the fossa of Rosenm├╝ller in the lateral wall.
ETIOLOGY OF NASOPHARYNGEAL CARCINOMA
  • Nasopharyngeal cancer is uncommon in India except in North East region where people are predominantly of Mongoloid origin.
  • People in Southern china, Taiwan and Indonesia are more prone to this cancer. 
  • Factors operative in China are burning of incense or wood(polycyclic hydrocarbon), use of preserved salted fish (nitrosamines) along with vitamin C deficient diet.
  • Infection with Epstein Barr Virus also act as predisposing factor.IgA antibody to EBV is observed
  • Nasopharyngeal carcinoma has a bimodal age distribution with peak distribution in the second and sixth decades in life.
  • Male : female ratio is 2 : 1.
  • Environmental: Air pollution, smoking of tobacco and opium, nitrosamines from dry salted fish, smoke from burning of incense and wood have all been incriminated.
  • Role of smoking and development of nasopharyngeal carcinoma is still not clear.
PATHOLOGY OF NASOPHARYNGEAL CARCINOMA
  • Squamous cell carcinoma is the most common (85%).
  • Keratinizing squamous cell carcinoma - Type I.
  • In ulcerative form of nasopharyngeal carcinoma, epistaxis is the common symptom. 
  • Proliferative type causes obstructive nasal symptoms. Growth infiltrates submucosally in infiltrative type of carcinoma.
  • The World Health Organization (WHO) has classified nasopharyngeal carcinoma into 3 categories.
  • WHO-1 is defined as well–to–moderately differentiated squamous or transitional cell carcinoma with keratin production.
  • WHO-2 is nonkeratinizing carcinoma.
  • WHO-3 is undifferentiated carcinoma, including lymphoepithelioma. This entity consists of malignant epithelial cells with lymphocytic infiltration.
  • The vast majority of children are found to have WHO-3 disease.
CLINICAL PRESENTATION IN A CASE OF NASOPHARYNGEAL CARCINOMA
  • The most common complain at presentation is the presence of an upper neck swelling. Unilateral neck swelling is much more common although bilateral metastasis also occur. Most common nodes involved are the jugulodigastric, and upper and middle jugular nodes in the anterior cervical chain.
  • Secondaries in the neck with no obvious primary malignancy is most often due to Ca. Nasopharynx.
  1. Most common tumor to produce metastasis to cervical lymph nodes is Nasopharyngeal carcinoma.
  2. Spreads to Eustachian tube, blocks it and causes Serous Otitis Media which in turn causes Conductive hearing loss.
  • Enlargement and extension of the tumor in the nasopharynx may result in symptoms of nasal obstruction (eg, congestion, nasal discharge, bleeding), changes in hearing (usually associated with blockage of the eustachian tube, and cranial nerve palsies (usually associated with extension of the tumor into the base of the skull).
  • Can cause Horner's syndrome due to involvement of cervical sympathetic chain.
  • Can cause conductive deafness (Eustachian tube blockage), ipsilateral (not contralateral) temporoparietal neuralgia (involvement of cranial nerve V) and palatal paralysis (CN X)- collectively called Trotter’s triad.
  • Extension of tumor may lead to proptosis, Trismus.
INVESTIGATIONS IN A CASE OF NASOPHARYNGEAL CARCINOMA
  • Nasal Endoscopy
  • Biopsy of the primary lesion or neck node is obtained for diagnosis
  • Epstein-Barr virus (EBV) titers, including immunoglobulin A (IgA) and immunoglobulin G (IgG) antibodies to the viral capsid antigen, early antigen, and nuclear antigen . CT scanning of the head and neck is used to determine tumor extent, base of skull erosion, and cervical lymphadenopathy.
  • When intracranial extension is suspected, MRI of the head and skull base may better reveal the extent of the tumor.
STAGING IN A CASE OF NASOPHARYNGEAL CARCINOMA 
 AJCC Staging for Nasopharyngeal Cancer
  1. Stage I :T1 N0 M0
  2. Stage II: T1 N1 M0,T2 N0 M0,T2 N1 M0
  3. Stage III :T1 N2 M0,T2 N2 M0,T3 N0 M0,T3 N1 M0,T3 N2 M0
  4. Stage IVA: T4 N0 M0,T4 N1 M0,T4 N2 M0
  5. Stage IVB: Any T N3 M0
  6. Stage IVC: Any T Any N MI
  7. Tumor(T) Staging
T0 No evidence of primary tumor
  • Tis Carcinoma in situ
  • T1 Tumor confined to the nasopharynx or extends to oropharynx and/or nasal cavity without parapharyngeal extension
  • T2 Tumor with parapharyngeal extension
  • T3 Tumor involves bony structures of skull base and/or paranasal sinuses
  • T4 Tumor with intracranial extension and/or involvement of cranial nerves, hypopharynx, orbit, or with extension to the infratemporal fossa/masticator space
Lymph Node(N) Staging
  • N0 No regional lymph node metastasis
  • N1 Unilateral metastasis in cervical lymph node(s), less than or equal to 6 cm in greatest dimension, above the supraclavicular fossa, and/or unilateral or bilateral retropharyngeal lymph nodes, less than or equal to 6 cm in greatest dimension
  • N2 Bilateral metastasis in a cervical lymph node (s), less than or equal to 6 cm in greatest dimension, above the supraclavicular fossa
  • N3 Metastasis in a lymph node(s) greater than 6 cm and/or to supraclavicular fossa
  • N3a Greater than 6 cm in dimension
  • N3b Extension to supraclavicular fossa
  • Metastasis (M) Staging
  • M0 No distant metastasis
  • M1 Distant metastasis
TREATMENT IN A CASE OF NASOPHARYNGEAL CARCINOMA
  • Radiotherapy is the mainstay of local therapy as surgery is not feasible.
  • Some centers use amifostine, a radioprotective agent, to help reduce radiation-related xerostomia.
  • NPCs are highly chemoradiosensitive.
  • Patient with advanced disease also receive concurrent chemotherapy.
  • T1 N2 MO Nasopharyngeal cancer is stage III ds. (Locoregional advanced ds.) and hence would need concurrent chemoradiation.
Exam Question
  • Treatment of choice of Nasopharyngeal Carcinoma is Radiotherapy.
  • Radiotherapy is the treatment of choice for Nasopharyngeal carcinoma T3N I.
  • Nasopharyngeal carcinoma is mostly Squamous cell carcinoma.
  • Trotter's triad is seen in Nasopharyngeal carcinoma.
  • Commonest site of Nasopharyngeal carcinoma is fossa of rosenmuller in lateral wall of nasopharynx.
  • Nasopharyngeal Carcinoma is associated with Epstein-Barr virus infection.IgA antibody to EBV is observed
  • Role of smoking and development of nasopharyngeal carcinoma is still not clear.
  • Concomitant chemoradiotherapy is indicated in T1 N2 M0 Nasopharyngeal Cancer.
  • In ulcerative form of nasopharyngeal carcinoma, epistaxis is the common symptom.
  • Nasopharyngeal cancer can cause conductive deafness (Eustachian tube blockage), ipsilateral (not contralateral) temporoparietal neuralgia (involvement of cranial nerve V) and palatal paralysis (CN X)- collectively called Trotter’s triad.
  • Nasopharyngeal carcinoma most commonly found in China.
  • Radiotherapy is the treatment of choice for nasopharyngeal carcinoma and not Nasopharyngectomy.
  • Bimodal age distribution is seen in Nasopharyngeal Carcinoma.
  • Secondaries in the neck with no obvious primary malignancy is most often due to Ca. Nasopharynx.
  • Most common tumor to produce metastasis to cervical lymph nodes is Nasopharyngeal carcinoma.
  • Cause of U/L secretory otitis media in an adult might be Nasopharyngeal carcinoma.
  • Nasopharyngeal Ca involves Nasal cavity.
  • Most common presentation in nasopharyngeal carcinoma is with Cervical lymphadenopathy.
  • Probable diagnosis in a 70-year-old male presenting with neck nodes,examination revealing a dull tympanic membrance, deaf­ness and tinnitus and Audiometry showing Curve B is Nasopharyngeal carcinoma.
  • Nasopharyngeal Ca causes deafness by Serous effusion.
  • Nasopharyngeal carcinoma can cause Horner's syndrome due to involvement of cervical sympathetic chain.
  • Unilateral serous otitis media is seen in Nasopharyngeal Carcinoma.
  • Nasopharyngectomy and lymph node dissection is not the main­stay of treatment in Nasopharyngeal Carcinoma.
  • Nasopharyngeal Carcinoma can be a cause in a 70-years-old man presenting with cervical lymphadenopathy.
  • Patient with nasopharyngeal carcinoma can present with Homer's syndrome,Epistaxis and proptosis, Trismus.
  • Nasopharyngeal Carcinoma does not lead to Sensorineural Hearing loss.
  • Keratinizing squamous cell carcinoma of nasopharynx is Type I.
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