Mucocutaneous melanin pigmentation and intestinal harmatomatous polyposis with increased risk of cancer of the GI tract, breast, uterus, cervix and ovary.
Incidence 1 in 8000 to 1 in 29,000 live births.
A rare, inherited gastrointestinal disorder characterized by the development of polyps on the mucous lining of the intestine and dark discolorations on the skin and mucous membranes.
Symptoms include nausea, vomiting, and abdominal pain that occurs because of a form of intestinal obstruction (intussusception).
Additional symptoms include bleeding from the rectum and dark skin discolorations around the lips, inside the cheeks, and on the arms.
Severe rectal bleeding can cause anemia and episodes of recurring, severe abdominal pain.
Autosomal dominant.
Approximately half of all cases are due to germline mutation in STK11 gene.
Affects men and women equally.
Pigmented mucocutaneous lesions present in almost all patients by age 2 years.
Lesions most commonly on the lips and perioral region (94%), hands (74%), buccal mucosa (66%), and in the feet (62%).
Lesions appear early, grow in size and number until puberty and then regress to some degree.
Hallmark of diagnosis is the presence of hamartomas of the gastrointestinal tract with 88% of the patients having hamartomatous polyps.
Extensive polyposis is especially common in the upper jejunum.
Hamartomatous polyps range from 0.1-5 cm and occur most commonly in the small intestine, colon, stomach, and rectum.
Hamartomatous polyps range from 0.1-5 cm and occur most commonly in the small intestine, colon, stomach, and rectum.
Rarely polyps may be seen in the renal pelvis, urinary bladder, lungs and nares.
Hamartomatous polyps typical appear between 10-30 years of age and may be responsible for obstructive symptoms (43%), abdominal pain (23%), hematochezia (14%), or anal extrusion of a polyp (7%).
47% of patients with hamartomatous polyps develop intussusception, most commonly in the small intestine.
Hamartomatous polyps ay lead to bowel obstruction, infarction and auto amputation of the polyp.
Cancer risk high for intestinal and extra intestinal lesions.
Lifetime risk of cancer at least 85%, with increase in incidence starting around age 30 years.
Gastrointestinal and breast cancer are the most common lesions.
Malignancies of the ovary, cervix, pancreas, lung uterus and testes increased.
Germ-line mutations in STK11, located on chromosome 19p13.3 identified in 70% of families.
STK11 a suspected tumor suppressor gene.