View source for Nasopharyngeal carcinoma

'''For patient information click [[{{PAGENAME}} (patient information)|here]] {{SI}}'''{{Infobox_Disease |
  Name           = Nasopharyngeal carcinoma |
  Image          = Lymphoepithelioma met to LN 6.jpg|
  Caption        = Metastatic nasopharyngeal carcinoma in a lymph node|
  DiseasesDB     = 8814 |
  ICD10          = {{ICD10|C|11||c|00}} |
  ICD9           = {{ICD9|147}} |
  ICDO           = |
  OMIM           = 161550 |
  MedlinePlus    = |
  eMedicineSubj  = ped |
  eMedicineTopic = 1553 |
  MeshID         = D009303 |
}}
{{Nasopharyngeal carcinoma}}
{{CMG}}
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==Overview==

'''Nasopharyngeal carcinoma''' (NPC) is a [[cancer]] originating in the [[nasopharynx]], the uppermost region of the [[pharynx]] or "throat", where the [[Nasal cavity|nasal passages]] and [[eustachian tube|auditory tubes]] join the remainder of the [[upper respiratory tract]]. NPC differs significantly from other [[head and neck cancer|cancers of the head and neck]] in its [[epidemiology|occurrence]], [[etiology|causes]], clinical behavior, and treatment. It is vastly more common in certain regions of East Asia and Africa than elsewhere, with [[virus|viral]], [[diet]]ary, and [[human genetics|genetic]] factors implicated in its causation.

==Classification==
Nasopharyngeal carcinoma is classified as a malignant [[neoplasia|neoplasm]], or [[cancer]], arising from the [[mucosa]]l [[epithelium]] of the [[nasopharynx]], most often within the ''lateral nasopharyngeal recess'' or ''fossa of Rosenmüller''. There are three [[histopathology|microscopic]] subtypes of NPC: a well-differentiated ''[[keratin]]izing'' type, a moderately-differentiated ''nonkeratinizing'' type, and an ''undifferentiated'' type, which typically contains large numbers of non-cancerous [[lymphocytes]] (chronic inflammatory cells), thus giving rise to the name ''[[lymphoepithelioma]]''. The undifferentiated form is most common, and is most strongly associated with [[Epstein-Barr virus]] infection of the cancerous cells.<ref name="Weidner's">{{cite book |author=Richard Cote, Saul Suster, Lawrence Weiss, Noel Weidner (Editor) |title=Modern Surgical Pathology (2 Volume Set) |publisher=W B Saunders |location=London |year= |pages= |isbn=0-7216-7253-1 |oclc= |doi=}}</ref>
<gallery>
Image:Lymphoepithelioma met to LN 4.jpg|Undifferentiated nasopharyngeal carcinoma - low power
Image:Lymphoepithelioma met to LN 1.jpg|Undifferentiated nasopharyngeal carcinoma - med. power
Image:Lymphoepithelioma met to LN 2.jpg|Undifferentiated nasopharyngeal carcinoma - high power
</gallery>

==Signs and symptoms==
Nasopharyngeal carcinoma produces few symptoms early in its course, with the result that most cases are quite advanced when detected. Once the tumor has expanded from its site of origin in the lateral wall of the nasopharynx, it may obstruct the nasal passages and cause [[rhinorrhea|nasal discharge]] or [[nosebleed]]. Obstruction of the [[Eustachian tube|auditory tubes]] may cause chronic [[otitis media|ear infection]]s, and patients may experience [[referred pain]] to the [[ear]]. [[Metastasis]] of cancer to the [[lymph node]]s of the [[neck]] may also be the first noticeable sign of the disease.<ref name="Weidner's">{{cite book |author=Richard Cote, Saul Suster, Lawrence Weiss, Noel Weidner (Editor) |title=Modern Surgical Pathology (2 Volume Set) |publisher=W B Saunders |location=London |year= |pages= |isbn=0-7216-7253-1 |oclc= |doi=}}</ref>

==Causes==
Numerous studies have linked common subtypes of NPC to infection with the [[Epstein-Barr virus]] (EBV), which has also been implicated in the development of other cancers such as [[Hodgkin's disease]], [[Burkitt's lymphoma]], and [[HIV]]-associated [[lymphoma]]s. There is some evidence that [[human genetics|genetic]] factors, such as [[HLA type]] may play a role in the susceptibility of certain ethnic groups to NPC. Finally, dietary risk factors, such as the consumption of salt-cured fish high in [[nitrosamines]], may play a role in the Asian endemic regions. Well-differentiated NPC, with a [[histopathology|microscopic appearance]] most similar to other [[head and neck cancer|squamous cell cancers of the head and neck]] may be more closely associated with the standard risk factors for that disease, such as [[cigarette smoking]].<ref name="Weidner's">{{cite book |author=Richard Cote, Saul Suster, Lawrence Weiss, Noel Weidner (Editor) |title=Modern Surgical Pathology (2 Volume Set) |publisher=W B Saunders |location=London |year= |pages= |isbn=0-7216-7253-1 |oclc= |doi=}}</ref><ref>{{cite book |author=Ian F Tannock, Richard P. Hill, Robert G. Bristow, Lea Harrington (Editor) |title=The Basic Science of Oncology (Fourth Edition) |publisher=McGraw Hill |location=U.S.A |year=2005 |pages= |isbn=0-07-138774-9}}</ref>

==Treatment==
Because NPC occurs in an anatomical site which is poorly accessible to surgeons, and is often advanced at presentation, the most effective means of treatment is generally [[radiation therapy]], either with or without concurrent [[chemotherapy]]. While the undifferentiated subtype of NPC is highly radiosensitive, this is less true of the more differentiated subtypes.<ref name="Weidner's">{{cite book |author=Richard Cote, Saul Suster, Lawrence Weiss, Noel Weidner (Editor) |title=Modern Surgical Pathology (2 Volume Set) |publisher=W B Saunders |location=London |year= |pages= |isbn=0-7216-7253-1 |oclc= |doi=}}</ref>

==Prognosis==
The five-year survival rate of nonkeratinizing and undifferentiated nasopharyngeal carcinomas, with appropriate treatment, is about 65% overall. Cure is highly possible, even when disease has spread to the regional lymph nodes. The prognosis of keratinizing NPC is significantly worse, due to its greater resistance to radiation.<ref name="Weidner's">{{cite book |author=Richard Cote, Saul Suster, Lawrence Weiss, Noel Weidner (Editor) |title=Modern Surgical Pathology (2 Volume Set) |publisher=W B Saunders |location=London |year= |pages= |isbn=0-7216-7253-1 |oclc= |doi=}}</ref>

==Epidemiology==
NPC is uncommon in the United States and most other nations, but is extremely common in Taiwan and certain regions of China, accounting for 18% of all cancers in the latter nation. While NPC is seen primarily in middle-aged persons in Asia, a high proportion of African cases appear in children. The cause of increased risk for NPC in these [[endemic (epidemiology)|endemic]] regions is not entirely clear.<ref name="Weidner's">{{cite book |author=Richard Cote, Saul Suster, Lawrence Weiss, Noel Weidner (Editor) |title=Modern Surgical Pathology (2 Volume Set) |publisher=W B Saunders |location=London |year= |pages= |isbn=0-7216-7253-1 |oclc= |doi=}}</ref>

==References==
{{reflist}}

== Acknowledgements ==
The content on this page was first contributed by: C. Michael Gibson, M.S., M.D.

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[[de:Nasopharynxkarzinom]]
[[fr:Carcinome du nasopharynx]]
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[[Category:Disease]]
[[Category:Oncology]]