AIIMS Nov 2006 Clinical Sciences MCQ 143

Juvenile polyps:

• Commonest form of polyp in children
• Can occur throughout large bowel but are most common in the rectum
• Usually present before 12 years
• Present with Prolapsing lump or rectal bleeding
• Not pre-malignant
• Treated by local endoscopic resection

Peutz-Jeghers syndrome:

• Rare familial disorder
• Circumoral pigmentation and intestinal polyps
• Polyps found throughout gut but most common in the small intestine
• Presents in childhood with bleeding, anaemia or intussusception
• Polyps can become malignant

Familial adenomatous polyposis:

• Aetiological factor in 1% of colorectal cancers
• Its is an autosomal dominant
• Due to mutation on long arm of chromosome 5
• Mutation induces proliferation of mucosa throughout GI tract
• Develop colonic polyps in teens or early 20’s
• Untreated progresses to cancer by 30’s
• Screening – by rigid or flexible sigmoidoscopy
• Safe alternative to colonoscopy as rectal sparing rarely seen
• Start late teens and continue until 40 yrs and polyp free.
• Extra-colonic manifestations:
  
  • Osteomas. epidermoid cysts = Gardener’s Syndrome
  • Gastroduodenal polyps
  • Desmoid tumours
  • Congenital hypertrophy of retinal pigmented epithelium
• Surgical options:
  
  • Panproctocolectomy and ileostomy
  • Restorative panproctocolectomy
  • Subtotal colectomy and ileorectal anastomosis
  • NB will require surveillance of rectal stump

• polyps develop throughout the gastrointestinal tract in the first decade or two of life.
• Its autosomal dominant
• 15% to 20% of cases are due to germline mutations in the MADH4 gene (also known as SMAD4/DPC4) which is located on chromosome 18 in band 18q21 1. Mutations in the gene for bone morphogenic protein receptor 1A (BMPR1A), residing on chromosome 10 in band 10q22.3, account for 25% to 40% of cases.
• majority of cases sporadic with no family history of juvenile polyposis.
• People with the disease are at increased risk for developing gastrointestinal cancers.

Category: AIIMS Nov 2006 MCQs