Appendix cancer

WikiDoc Resources for Appendix cancer
Articles
Most recent articles on Appendix cancer Most cited articles on Appendix cancer Review articles on Appendix cancer Articles on Appendix cancer in N Eng J Med, Lancet, BMJ
Media
Powerpoint slides on Appendix cancer Images of Appendix cancer Photos of Appendix cancer Podcasts & MP3s on Appendix cancer Videos on Appendix cancer
Evidence Based Medicine
Cochrane Collaboration on Appendix cancer Bandolier on Appendix cancer TRIP on Appendix cancer
Clinical Trials
Ongoing Trials on Appendix cancer at Clinical Trials.gov Trial results on Appendix cancer Clinical Trials on Appendix cancer at Google
Guidelines / Policies / Govt
US National Guidelines Clearinghouse on Appendix cancer NICE Guidance on Appendix cancer NHS PRODIGY Guidance FDA on Appendix cancer CDC on Appendix cancer
Books
Books on Appendix cancer
News
Appendix cancer in the news Be alerted to news on Appendix cancer News trends on Appendix cancer
Commentary
Blogs on Appendix cancer
Definitions
Definitions of Appendix cancer
Patient Resources / Community
Patient resources on Appendix cancer Discussion groups on Appendix cancer Patient Handouts on Appendix cancer Directions to Hospitals Treating Appendix cancer Risk calculators and risk factors for Appendix cancer
Healthcare Provider Resources
Symptoms of Appendix cancer Causes & Risk Factors for Appendix cancer Diagnostic studies for Appendix cancer Treatment of Appendix cancer
Continuing Medical Education (CME)
CME Programs on Appendix cancer
International
Appendix cancer en Espanol Appendix cancer en Francais
Business
Appendix cancer in the Marketplace Patents on Appendix cancer
Experimental / Informatics
List of terms related to Appendix cancer

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Maria Fernanda Villarreal, M.D. [2]

Synonyms and keywords: Tumors of the appendix; Appendiceal cancer; Cancer of the appendix

Overview

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. Appendix cancer may be classified according to WHO classification into 4 groups: 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.

Historical Perspective

• Appendix cancer was first described by Gagne, a French Physician, in 1969.

Classification

• Appendix cancer may be classified according to WHO classification into 4 groups:

• Epithelial tumors
• Non-epithelial tumors
• Secondary tumors
• Hyperplastic (metaplastic) polyp

• The table below summarizes the different types of appendix cancer according to the WHO classification

WHO histological classification Tumors of the appendix Adapted from WHO/IARC
Epithelial tumors
Adenoma Tubular Villous Tubulovillous Serrated Carcinoma Adenocarcinoma Mucinous adenocarcinoma Signet-ring cell carcinoma Small cell carcinoma Undifferentiated carcinoma Carcinoid (well differentiated endocrine neoplasm) Tubular carcinoid Goblet cell carcinoid (mucinous carcinoid) Mixed carcinoid-adenocarcinoma Others
Non-epithelial tumors
Neuroma Lipoma Leiomyoma Gastrointestinal stromal tumor Leiomyosarcoma Kaposi sarcoma Others
Secondary tumors
Metastasis (eg. Primary of urogenital tract, breast, lung)
Hyperplastic polyp

Pathophysiology

• The pathogenesis of appendix cancer is characterized by an initial epithelial dysplasia.
• The KRAS gene mutation has been associated with the development of appendix cancer.
• On gross pathology, well-demarcated mass, less than 1 cm, and gray or yellowish color, and deformed appendix are characteristic findings of appendix cancer.
• On microscopic histopathological analysis findings will depend on the subtype of appendicular cancer.
• Common histopathological findings, may include:

• Cystic structures
• Angiolymphatic invasion
• Well differentiated and mucinous

• 
  Appendiceal carcinoid
• 
  Appendiceal carcinoid
• 
  Appendiceal carcinoid with necrosis
• 
  Carcinoid synaptophysin
• 
  Appendiceal tumor

Causes

• Common causes of appendix cancer may include:
• Chronic inflammatory diseases, such as:

• Ulcerative colitis
• Crohn's disease

• Hereditary syndromes, such as:

• Familial adenomatous polyposis
• Hereditary non-polyposis colorectal cancer

Differentiating Appendix Cancer from Other Diseases

• Appendix cancer must be differentiated from other diseases that cause abdominal pain, nausea, vomiting such as:

• Appendicitis
• Typhlitis
• Infectious terminal ileitis
• Ileocecal enteric duplication cyst

Epidemiology and Demographics

• The estimated prevalence of appendix cancer is approximately 0.12 cases per 100,000 individuals in the United States.
• The estimated prevalence of adenocarcinoma of the appendix is 0.2 cases per 100,000 individuals worldwide.

Age

• The median age at diagnosis of patients with appendix cancer is 65 years.
• Appendix cancer is more commonly observed among patients aged 50 to 60 years old.
• Appendix cancer is more commonly observed among adults and elderly patients.

Gender

• Males are more commonly affected with appendix cancer than females.

Race

• There is no racial predilection for appendix cancer.

Risk Factors

• Common risk factors in the development of appendix cancer are family history of cancer, long-standing ulcerative colitis, and chronic inflammatory bowel diseases.

Natural History, Complications and Prognosis

• The majority of patients with appendix cancer may be initially asymptomatic.
• Early clinical features include periodical unspecific abdominal pain, bloating, and nausea.
• If left untreated, the majority of patients with appendix cancer may progress to develop peritoneal carcinomatosis and metastases.
• Common complications of appendix cancer include perforation, peritonitis, and abscess.
• Prognosis is generally good, and the 5-survival rate of patients with appendix cancer is approximately 90%.

Diagnosis

Diagnostic Criteria

• The diagnosis of appendix cancer is made with histopathological evaluation of the following diagnostic criteria:

• Tumor confined to the appendix
• Invasion to the muscularis mucosae
• Presence of metastases
• Spread to the peritoneal cavity

Symptoms

• Symptoms of appendix cancer may include the following:

• Chronic abdominal pain

• Periumbilical
• Right lower quadrant

• Loss of appetite
• Nausea
• Vomiting
• Diarrhea
• Micturition
• Tenesmus
• Indigestion
• Flatulence
• Bowel irregularity

Physical Examination

• Patients with appendix cancer may appear normal, pale or diaphoretic.
• Abdominal examination may be remarkable for:

Palpation

• The abdominal wall is very sensitive to mild palpation
• Rebound tenderness
• Abdominal guarding
• Rovsing's sign
• Psoas sign

Laboratory Findings

• Laboratory findings consistent with the diagnosis of appendix cancer, may include:

Imaging Findings

• There are no [imaging study] findings associated with appendix cancer.

• [Imaging study 1] is the imaging modality of choice for appendix cancer.
• On [imaging study 1], appendix cancer is characterized by [finding 1], [finding 2], and [finding 3].
• [Imaging study 2] may demonstrate [finding 1], [finding 2], and [finding 3].

Other Diagnostic Studies

• Appendix cancer may also be diagnosed using [diagnostic study name].
• Findings on [diagnostic study name] include [finding 1], [finding 2], and [finding 3].

Treatment

Medical Therapy

• There is no treatment for appendix cancer; the mainstay of therapy is supportive care.

• The mainstay of therapy for appendix cancer is [medical therapy 1] and [medical therapy 2].
• [Medical therapy 1] acts by [mechanism of action1].
• Response to [medical therapy 1] can be monitored with [test/physical finding/imaging] every [frequency/duration].

Surgery

• Surgery is the mainstay of therapy for appendix cancer.
• [Surgical procedure] in conjunction with [chemotherapy/radiation] is the most common approach to the treatment of appendix cancer.
• [Surgical procedure] can only be performed for patients with [disease stage] appendix cancer.

Prevention

• There are no primary preventive measures available for appendix cancer.

• Effective measures for the primary prevention of appendix cancer include [measure1], [measure2], and [measure3].

• Once diagnosed and successfully treated, patients with appendix cancer are followed-up every [duration]. Follow-up testing includes [test 1], [test 2], and [test 3].