Familial adenomatous polyposis overview: Difference between revisions
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==Risk Factors== | ==Risk Factors== | ||
The most potent risk factor in the development of familial adenomatous polyposis is positive [[family history]] of FAP. | |||
==Screening== | ==Screening== | ||
Screening for familial adenomatous polyposis by [[genetic testing]] and/or [[colonoscopy]] is recommended among patients with history of multiple colonic [[Adenoma|adenomas]] and [[family history]] of familial adenomatous polyposis. | |||
==Natural History, Complications, and Prognosis== | ==Natural History, Complications, and Prognosis== | ||
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===History and Symptoms=== | ===History and Symptoms=== | ||
The majority of patients with familial adenomatous polyposis are asymptomatic till [[colorectal cancer]] happens. Common symptoms of familial adenomatous polyposis are [[gastrointestinal bleeding]], [[pain]], and altered [[Defecation|bowel habits]]. They might have [[fatigue]] following [[Fecal occult blood|occult bleeding]]. | |||
===Physical Examination=== | ===Physical Examination=== | ||
Patients with familial adenomatous polyposis usually appear normal. Physical examination of patients with familial adenomatous polyposis may have palpable [[abdominal mass]], multiple small [[rectal]] [[Polyp|polyps]], and [[pallor]]. | |||
===Laboratory Findings=== | ===Laboratory Findings=== | ||
Laboratory findings that may present with familial adenomatous polyposis include [[anemia]] due to [[gastrointestinal bleeding]] and abnormal [[liver function tests]] due to [[Colorectal cancer|colon cancer]] metastasis. | |||
===Electrocardiogram=== | ===Electrocardiogram=== | ||
There are no [[The electrocardiogram|ECG]] findings associated with familial adenomatous polyposis. | |||
===X-ray=== | ===X-ray=== | ||
Double-contrast [[Barium enema]] may be helpful in the diagnosis of familial adenomatous polyposis. Familial adenomatous polyposis might be presented as multiple outgrowths with lobulation or indentation and filling defects on [[x-rays]]. | |||
===Ultrasound=== | ===Echocardiography and Ultrasound=== | ||
There are no echocardiography/ultrasound findings associated with familial adenomatous polyposis. | |||
===CT scan=== | ===CT scan=== | ||
[[Computed tomography|CT scan with contrast]] and [[Virtual colonoscopy|CT colonography]] or [[virtual colonoscopy]] may be helpful in the diagnosis of familial adenomatous polyposis. Multiple outgrowths and filling defects are suggestive of familial adenomatous polyposis. | |||
===MRI=== | ===MRI=== | ||
[[Magnetic resonance imaging|MRI]] may be helpful in the [[diagnosis]] of familial adenomatous polyposis. Diffusion-weighted [[magnetic resonance imaging]] (DWI) and [[Magnetic resonance imaging|MRI]] colonography are used to detect [[Polyp|polyps]]. | |||
===Other Imaging Findings=== | ===Other Imaging Findings=== | ||
[[Colonoscopy|Colonoscopic]] [[spectroscopy]] and narrow-band imaging (NBI) may be helpful in the diagnosis of familial adenomatous polyposis. | |||
===Other Diagnostic Studies=== | ===Other Diagnostic Studies=== | ||
[[Colonoscopy]] is considered as a gold standard for evaluating [[intestine]], [[Diagnosis|diagnostic]] and [[Therapy|therapeutic]] approaches. Tissue [[biopsy]] and [[polypectomy]] could be done during [[colonoscopy]]. Findings on a [[colonoscopy]] and [[Sigmoidoscopy|flexible sigmoidoscopy]] suggestive of familial adenomatous polyposis include visual detection of multiple [[colon polyps]]. [[Colonoscopy]]<nowiki/>has 0.02% [[Mortality rate|mortality]] and 0.2% [[morbidity]] 0.2%. [[Colonoscopy]] has side effects including [[pain]], risk of [[perforation]] and [[bleeding]]. | |||
==Treatment== | ==Treatment== | ||
Revision as of 02:16, 1 February 2018
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Familial adenomatous polyposis Microchapters |
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Differentiating Familial adenomatous polyposis from other Diseases |
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Diagnosis |
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Treatment |
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Sadaf Sharfaei M.D.[2], Mohamad Alkateb, MBBCh [3]
Overview
Historical Perspective
Familial adenomatous polyposis was first described in 1726 by Menzelio. After 150 years, in 1882, familial nature of the multiple colonic polyposis was reported. Inheritancepredisposition was identified in 1925. Gardner's syndrome was first described in 1950 by Gardner and Stephens. Bussey described clinical features and natural history of familial adenomatous polyposis in 1975. In 1986, genetic abnormality was discovered by Herrera. In 1991, APC gene defect was identified as one of the causes of familial adenomatous polyposis.
Classification
Familial adenomatous polyposis (FAP) may be classified according to the affected gene into two subtypes including FAP gene and MYH gene associated familial adenomatous polyposis. Familial adenomatous polyposis may be classified according to severity into three subtypes of profuse, intermediate, and attenuated. Familial adenomatous polyposis has less severe variants, including gardner's syndrome and turcot syndrome.
Pathophysiology
Causes
Familial adenomatous polyposis may be caused by mutation in APC or MUTYH genes.
Differentiating Familial Adenomatous Polyposis from Other Diseases
Familial adenomatous polyposis must be differentiated from other diseases that cause multiple polyps, such as Peutz–Jeghers syndrome, juvenile polyposis syndrome, Cowden syndrome, Carney syndrome, and hereditary non–polyposis colon cancer (Lynch syndrome).
Epidemiology and Demographics
Familial adenomatous polyposis is a rare disease that affects individuals worldwide. The incidence and prevalence of familial adenomatous polyposis is approximately 3-20 and 12 per 100,000 individuals. Surgical mortality rate is approximately 4.4%. Patients in their first and second decades usually develop familial adenomatous polyposis. Familial adenomatous polyposis affects men and women equally and there is no racial predilection. Up to 100% of patients with familial adenomatous polyposis without treatment will develop colorectal cancer by age of 39.
Risk Factors
The most potent risk factor in the development of familial adenomatous polyposis is positive family history of FAP.
Screening
Screening for familial adenomatous polyposis by genetic testing and/or colonoscopy is recommended among patients with history of multiple colonic adenomas and family history of familial adenomatous polyposis.
Natural History, Complications, and Prognosis
Diagnosis
Diagnostic Criteria
History and Symptoms
The majority of patients with familial adenomatous polyposis are asymptomatic till colorectal cancer happens. Common symptoms of familial adenomatous polyposis are gastrointestinal bleeding, pain, and altered bowel habits. They might have fatigue following occult bleeding.
Physical Examination
Patients with familial adenomatous polyposis usually appear normal. Physical examination of patients with familial adenomatous polyposis may have palpable abdominal mass, multiple small rectal polyps, and pallor.
Laboratory Findings
Laboratory findings that may present with familial adenomatous polyposis include anemia due to gastrointestinal bleeding and abnormal liver function tests due to colon cancer metastasis.
Electrocardiogram
There are no ECG findings associated with familial adenomatous polyposis.
X-ray
Double-contrast Barium enema may be helpful in the diagnosis of familial adenomatous polyposis. Familial adenomatous polyposis might be presented as multiple outgrowths with lobulation or indentation and filling defects on x-rays.
Echocardiography and Ultrasound
There are no echocardiography/ultrasound findings associated with familial adenomatous polyposis.
CT scan
CT scan with contrast and CT colonography or virtual colonoscopy may be helpful in the diagnosis of familial adenomatous polyposis. Multiple outgrowths and filling defects are suggestive of familial adenomatous polyposis.
MRI
MRI may be helpful in the diagnosis of familial adenomatous polyposis. Diffusion-weighted magnetic resonance imaging (DWI) and MRI colonography are used to detect polyps.
Other Imaging Findings
Colonoscopic spectroscopy and narrow-band imaging (NBI) may be helpful in the diagnosis of familial adenomatous polyposis.
Other Diagnostic Studies
Colonoscopy is considered as a gold standard for evaluating intestine, diagnostic and therapeutic approaches. Tissue biopsy and polypectomy could be done during colonoscopy. Findings on a colonoscopy and flexible sigmoidoscopy suggestive of familial adenomatous polyposis include visual detection of multiple colon polyps. Colonoscopyhas 0.02% mortality and 0.2% morbidity 0.2%. Colonoscopy has side effects including pain, risk of perforation and bleeding.