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| __NOTOC__ | | __NOTOC__ |
| {{SI}} | | {{Appendix cancer}} |
| {{CMG}} {{AE}} {{MV}}
| | '''For patient information, click [[Appendix cancer (patient information)|here]]''' |
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| {{SK}} Tumors of the appendix; Appendiceal cancer; Cancer of the appendix; Neoplasms of the appendix
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| ==Overview==
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| '''Appendix cancer''' '''(also known as appendiceal cancer)''' is a rare malignancy of the vermiform appendix. The most common type of appendix cancer is carcinoid tumor. Appendix cancers often present with peritoneal seeding, resulting in peritoneal carcinomatosis or pseudomyxoma peritonei.<ref name="pmid22302267">{{cite journal |vauthors=Turaga KK, Pappas SG, Gamblin T |title=Importance of histologic subtype in the staging of appendiceal tumors |journal=Ann. Surg. Oncol. |volume=19 |issue=5 |pages=1379–85 |year=2012 |pmid=22302267 |doi=10.1245/s10434-012-2238-1 |url=}}</ref> Appendix cancer may be classified according to WHO classification into 4 groups:
| | {{CMG}}; {{AE}} {{Soroush}} |
| epithelial tumors, non-epithelial tumors, secondary tumors, and hyperplastic (metaplastic) polyp. Common causes of appendix cancer may include hereditary syndromes (eg. familial adenomatous polyposis, hereditary non-polyposis colorectal cancer) and chronic inflammatory diseases (eg. ulcerative colitis, Crohn's disease). The estimated prevalence of appendix cancer is approximately 0.12 cases per 100,000 individuals in the United States. On gross pathology, well-demarcated mass, between 1-5 cm, gray or yellowish color are characteristic findings of appendix cancer. Early clinical features include periodical unspecific abdominal pain, bloating, and nausea. Enhanced CT is the imaging modality of choice for appendix cancer. On CT, appendix cancer is characterized by the following findings: soft tissue thickening, wall irregularity, presence of pseudomyxoma peritonei, calcification, and internal septations. Prognosis is will depend on tumor histology.<ref name="pmid16973770">{{cite journal |vauthors=Hoeffel C, Crema MD, Belkacem A, Azizi L, Lewin M, Arrivé L, Tubiana JM |title=Multi-detector row CT: spectrum of diseases involving the ileocecal area |journal=Radiographics |volume=26 |issue=5 |pages=1373–90 |year=2006 |pmid=16973770 |doi=10.1148/rg.265045191 |url=}}</ref> However, the overall 5-survival rate of patients with appendix cancer is approximately 51%. Surgery is the mainstay of therapy for appendix cancer. Right hemicolectomy in conjunction with chemotherapy is the most common approach to the treatment of appendix cancer. Once diagnosed and successfully treated, patients with appendix cancer are followed-up every 3, 12 months. Follow-up testing for appendix cancer includes physical examination, medical history, imaging studies, chromogranin testing, and laboratory studies (eg. tumoral biomarkers).
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| ==Historical Perspective==
| | {{SK}}Appendix malignancy, Appendix tumor, Appendiceal cancer, Appendiceal malignancy, Carcinoid tumor of appendix, Adenocarcinoma of appendix, Goblet cell tumor of appendix, |
| *Appendix cancer was first described by Gagne, a French Physician, in 1969.<ref name="pmid5378353">{{cite journal |vauthors=Gagné F, Fortin P, Dufour V, Delage C |title=[Tumors of the appendix associating histologic features of carcinoid and adenocarcinoma] |language=French |journal=Ann Anat Pathol (Paris) |volume=14 |issue=4 |pages=393–406 |year=1969 |pmid=5378353 |doi= |url=}}</ref>
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| ==Classification== | | ==[[Appendix cancer overview|Overview]]== |
| *Appendix cancer may be classified according to WHO classification into 4 groups:
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| :*Epithelial tumors
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| :*Non-epithelial tumors
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| :*Secondary tumors
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| :*Hyperplastic (metaplastic) polyp
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| *The table below summarizes the different types of appendix cancer according to the WHO classification
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| {|style="border: 5px; font-size: 90%; margin: 5px; width: 300px" align=center
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| !style="padding: 5px 5px; background: #4479BA; font-weight: bold; text-align:center;" colspan="2"|{{fontcolor|#FFF|'''WHO histological classification<br>Tumors of the appendix <br><SMALL> Adapted from WHO/IARC </SMALL>'''}}
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| |valign=top|
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| | style="padding: 5px 5px; background: #DCDCDC; font-weight: bold; text-align:center;"| Epithelial tumors
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| |-
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| *'''Adenoma'''
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| :*Tubular
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| :*Villous
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| :*Tubulovillous
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| :*Serrated
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| *'''Carcinoma'''
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| :*Adenocarcinoma
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| :*Mucinous adenocarcinoma
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| :*Signet-ring cell carcinoma
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| :*Small cell carcinoma
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| :*Undifferentiated carcinoma
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| *'''Carcinoid (well differentiated endocrine neoplasm)'''
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| *'''Tubular carcinoid'''
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| *'''Goblet cell carcinoid (mucinous carcinoid)'''
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| *'''Mixed carcinoid-adenocarcinoma'''
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| *'''Others'''
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| |-
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| | style="padding: 5px 5px; background: #DCDCDC; font-weight: bold; text-align:center;" | Non-epithelial tumors
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| *Neuroma
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| *Lipoma
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| *Leiomyoma
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| *Gastrointestinal stromal tumor
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| *Leiomyosarcoma
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| *Kaposi sarcoma
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| *Others
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| |-
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| |style="padding: 5px 5px; background: #DCDCDC; font-weight: bold; text-align:center;"| Secondary tumors
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| |-
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| *Metastasis (eg. Primary of urogenital tract, breast, lung)
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| |-
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| |style="padding: 5px 5px; background: #DCDCDC; font-weight: bold; text-align:center;"| Hyperplastic polyp
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| |}
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| ==Pathophysiology== | | ==[[Appendix cancer historical perspective|Historical Perspective]]== |
| *The pathogenesis of appendix cancer is characterized by an initial epithelial dysplasia, followed by the formation of cystic structures and angiolymphatic invasion. Subsequently, in the advanced stages of appendix cancer, tumor cells detach from the primary tumor mass and gain access to the peritoneal cavity.
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| *The KRAS gene mutation has been associated with the development of appendix cancer.
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| *On gross pathology, findings of appendix cancer, include:
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| :*Well-demarcated mass
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| :*Average size between 1 and 5cm
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| :*Gray or yellowish color
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| :*Deformed appendix
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| *On microscopic histopathological analysis findings will depend on the subtype of appendicular cancer.
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| *Common histopathological findings, may include:
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| :*Cystic structures
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| :*Angiolymphatic invasion
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| <gallery>800px-Appendix_Carcinoid_Torsion_1X_PA.JPG | Appendiceal carcinoid<ref name=aaa>http://librepathology.org/wiki/index.php/Neuroendocrine_tumour_of_the_appendix</ref>
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| 800px-Appendix_Carcinoid_HP_14BR---.jpg | Appendiceal carcinoid<ref name=aaa>http://librepathology.org/wiki/index.php/Neuroendocrine_tumour_of_the_appendix</ref>
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| 800px-Appendix_Carcinoid_Necrosis_PA.JPG | Appendiceal carcinoid with necrosis<ref name =aaa>http://librepathology.org/wiki/index.php/Neuroendocrine_tumour_of_the_appendix</ref>
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| 800px-Appendix_Carcinoid_Synaptophysin_14BR---.jpg | Carcinoid synaptophysin<ref name=aaa>http://librepathology.org/wiki/index.php/Neuroendocrine_tumour_of_the_appendix</ref>
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| 800px-Appendix_Carcinoid_HP_CTR.jpg | Appendiceal tumor<ref name=aaa>http://librepathology.org/wiki/index.php/Neuroendocrine_tumour_of_the_appendix</ref>
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| </gallery>
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| ==Causes== | | ==[[Appendix cancer classification|Classification]]== |
| *Common causes of appendix cancer may include:
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| *Chronic inflammatory diseases, such as:
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| :*Ulcerative colitis
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| :*Crohn's disease
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| *Hereditary syndromes, such as:
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| :*Familial adenomatous polyposis
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| :*Hereditary non-polyposis colorectal cancer
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| ==Differentiating Appendix Cancer from Other Diseases== | | ==[[Appendix cancer pathophysiology|Pathophysiology]]== |
| * Appendix cancer must be differentiated from other diseases that cause abdominal pain, nausea, vomiting such as:
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| :*[[Appendicitis]]
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| :*[[Typhlitis]]
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| :*Infectious terminal ileitis
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| :*Ileocecal enteric duplication cyst
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| ==Epidemiology and Demographics== | |
| * The estimated prevalence of appendix cancer is approximately 0.12 cases per 100,000 individuals in the United States.
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| * The estimated prevalence of adenocarcinoma of the appendix is 0.2 cases per 100,000 individuals worldwide.
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| ===Age===
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| * The median age at diagnosis of patients with appendix cancer is 65 years.
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| * Appendix cancer is more commonly observed among patients aged 50 to 60 years old.
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| * Appendix cancer is more commonly observed among adults and elderly patients.
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| ===Gender=== | | ==[[Appendix cancer causes|Causes]]== |
| *Males are more commonly affected with appendix cancer than females.
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| ===Race=== | | ==[[Appendix cancer differential diagnosis|Differentiating Appendix cancer from other Diseases]]== |
| *There is no racial predilection for appendix cancer.
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| ==Risk Factors== | | ==[[Appendix cancer epidemiology and demographics|Epidemiology and Demographics]]== |
| *Common risk factors in the development of appendix cancer are family history of cancer, long-standing ulcerative colitis, and chronic inflammatory bowel diseases.
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| == Natural History, Complications and Prognosis== | | ==[[Appendix cancer risk factors|Risk Factors]]== |
| *The majority of patients with appendix cancer may be initially asymptomatic.
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| *Early clinical features include periodical unspecific abdominal pain, bloating, and nausea.
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| *If left untreated, the majority of patients with appendix cancer may progress to develop peritoneal carcinomatosis and metastases.
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| *Common complications of appendix cancer include perforation, peritonitis, and abscess.
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| *Prognosis will depend on tumor histology. However, the overall 5 year survival rate of patients with appendix cancer is approximately 50%.
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| == Diagnosis == | | ==[[Appendix cancer screening|Screening]]== |
| ===Diagnostic Criteria===
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| *The diagnosis of appendix cancer is made with histopathological evaluation of the following diagnostic criteria:
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| :*Tumor confined to the appendix
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| :*Invasion to the muscularis mucosae
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| :*Presence of metastases
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| :*Spread to the peritoneal cavity
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| === Symptoms === | | ==[[Appendix cancer natural history, complications and prognosis|Natural History, Complications and Prognosis]]== |
| *Symptoms of appendix cancer may include the following:
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| :*Chronic [[abdominal pain]]
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| ::*Periumbilical
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| ::*Right lower quadrant
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| :*[[Loss of appetite]]
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| :*[[Nausea]]
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| :*[[Vomiting]]
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| :*[[Diarrhea]]
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| :*[[Micturition]]
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| :*[[Tenesmus]]
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| :*[[Indigestion]]
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| :*[[Flatulence]]
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| :*Bowel irregularity
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| === Physical Examination === | | ==Diagnosis== |
| *Patients with appendix cancer may appear normal, pale or diaphoretic.
| | [[Appendix cancer diagnostic study of choice|Diagnostic study of choice]] | [[Appendix cancer history and symptoms|History and Symptoms]] | [[Appendix cancer physical examination|Physical Examination]] | [[Appendix cancer laboratory findings|Laboratory Findings]] | [[Appendix cancer electrocardiogram|Electrocardiogram]] | [[Appendix cancer x ray|X-Ray Findings]] | [[Appendix cancer echocardiography and ultrasound|Echocardiography and Ultrasound]] | [[Appendix cancer CT scan|CT-Scan Findings]] | [[Appendix cancer MRI|MRI Findings]] | [[Appendix cancer other imaging findings|Other Imaging Findings]] | [[Appendix cancer other diagnostic studies|Other Diagnostic Studies]] |
| *Abdominal examination may be remarkable for:
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| '''Palpation'''
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| *The abdominal wall is very sensitive to mild palpation
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| *[[Rebound tenderness]]
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| *[[Abdominal guarding]]
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| * [[Rovsing's sign]]
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| * [[Psoas sign]]
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| '''Rectal examination''''
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| *Tenderness in the [[rectovesical pouch]]
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| === Laboratory Findings === | | ==Treatment== |
| *Laboratory findings consistent with the diagnosis of appendix cancer, may include:
| | [[Appendix cancer medical therapy|Medical Therapy]] | [[Appendix cancer interventions|Interventions]] | [[Appendix cancer surgery|Surgery]] | [[Appendix cancer primary prevention|Primary Prevention]] | [[Appendix cancer secondary prevention|Secondary Prevention]] | [[Appendix cancer cost-effectiveness of therapy|Cost-Effectiveness of Therapy]] | [[Appendix cancer future or investigational therapies|Future or Investigational Therapies]] |
| :* [[Leukocytosis]] and a shift to the left in the segmented [[neutrophils]].
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| :* Elevated serotonin metabolite 5-hydroxyindoleacetic acid (5-HIAA)
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| :* Elevated c-reactive protein (CRP)
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| ===Imaging Findings=== | | ==Case Studies== |
| *Enhanced CT is the imaging modality of choice for appendix cancer.
| | [[Appendix cancer case study one|Case #1]] |
| *On CT, appendix cancer is characterized by the following findings:<ref name="pmid16973770">{{cite journal |vauthors=Hoeffel C, Crema MD, Belkacem A, Azizi L, Lewin M, Arrivé L, Tubiana JM |title=Multi-detector row CT: spectrum of diseases involving the ileocecal area |journal=Radiographics |volume=26 |issue=5 |pages=1373–90 |year=2006 |pmid=16973770 |doi=10.1148/rg.265045191 |url=}}</ref>
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| :*Soft tissue thickening
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| :*Wall irregularity
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| :*Presence of pseudomyxoma peritonei
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| :*Calcification
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| :*Internal septations
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| :*Periappendiceal fat stranding and intraperitoneal free fluid is nonspecific.
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| === Other Diagnostic Studies ===
| | [[Category:Surgery]] |
| * Appendix cancer may also be diagnosed using the following diagnostic studies:
| | [[Category:Medicine]] |
| :*[[Somatostatin]] [[scintigraphy]] with 111-indium-octreotide
| | [[Category:Emergency medicine]] |
| :*[[Bone]] [[scintigraphy]] with 99mTc-methylene diphosphonate (99mTcMDP) | | [[Category:Oncology]] |
| :*[[Capsule endoscopy]]
| | [[Category:Up-To-Date]] |
| :*[[Enteroscopy]] | |
| :*[[Positron emission tomography]] (PET)
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| == Treatment ==
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| === Medical Therapy ===
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| *The mainstay medical therapy for appendix cancer is supportive care.
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| *Supportive care for appendix cancer, may include:
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| *[[Somatostatin]] analogs
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| *[[Interferons]]
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| *[[Loperamide]] or [[diphenoxylate]] (for diarrhea)
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| === Surgery ===
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| *Surgery is the mainstay of therapy for appendix cancer.
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| *Right hemicolectomy in conjunction with chemotherapy is the most common approach to the treatment of appendix cancer.
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| === Prevention ===
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| *There are no primary preventive measures available for appendix cancer
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| *Once diagnosed and successfully treated, patients with appendix cancer are followed-up every 3, 12 months.
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| *Follow-up testing for appendix cancer includes physical examination, medical history, imaging studies, chromogranin testing, and laboratory studies (eg. tumoral biomarkers)
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| ==References==
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| {{Reflist|2}}
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| [[Category: Oncology]]
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