Differentials
MUTYH polyposis
SIGNS / SYMPTOMS
Cannot be definitively distinguished by any key characteristics in the personal history or physical examination. However, if the patient has a family history of FAP with a known adenomatous polyposis coli mutation, then this diagnosis is very unlikely.
Juvenile polyposis
SIGNS / SYMPTOMS
Family history of juvenile polyposis. Patients may present with iron deficiency anaemia, obstructive symptoms, or evidence of a gross gastrointestinal bleed. A subset may have clubbing of fingernails and telangiectasias.
INVESTIGATIONS
Juvenile polyps in the stomach, small bowel, and/or colon. Polyps are juvenile retention polyps with mucin. Germline testing for SMAD4, BMPR1A, and PTEN gene mutations may be positive. Patients with SMAD4 mutations may also have hereditary haemorrhagic telangiectasias.
Peutz-Jeghers syndrome
SIGNS / SYMPTOMS
Clinical presentation may be similar. Hyper-pigmentation of the buccal mucosa and lips is commonly seen. Small bowel intussusceptions and/or obstruction are common presentations.
INVESTIGATIONS
Polyp histology shows hamartomatous lesions, usually with smooth muscle arborisation. STK11 genetic testing may be positive.
Mixed adenomatous hyperplastic polyposis
SIGNS / SYMPTOMS
Clinically asymptomatic.
INVESTIGATIONS
Colonoscopy shows both flat and pedunculated polyps, with flat polyps >1 cm in diameter in the right side of the colon. Histology reveals both hyperplastic and adenomatous polyps; the right-sided polyps may also have sessile serrated adenomatous features histologically.
Serrated polyposis syndrome
SIGNS / SYMPTOMS
Clinically asymptomatic
INVESTIGATIONS
≥5 serrated lesions/polyps proximal to the rectum, all being ≥5 mm in size, with ≥2 being ≥10 mm in size; or >20 serrated lesions/polyps of any size distributed throughout the large bowel, with ≥5 being proximal to the rectum.[35]
Colonic lymphoid hyperplasia
SIGNS / SYMPTOMS
Can cause abdominal pain, haematochezia, chronic diarrhoea, recurrent intussusceptions in children.
INVESTIGATIONS
Endoscopically, multiple polypoid lesions may be present throughout the colon or in a segment of the colon. Pathology reveals lymphoid hyperplasia, rather than adenomatous tissue.
Use of this content is subject to our disclaimer