Summary

• Rare genetic polyposis syndrome, characterised by gastrointestinal hamartomatous polyposis and mucocutaneous pigmentation.
• Inherited as an autosomal-dominant syndrome caused by germline alterations in STK11 gene. De novo mutations may also occur.
• Associated with an increased risk of intestinal cancer (e.g., colorectal and small bowel) and extra-intestinal cancer (e.g., breast, pancreas). The lifetime risk for developing cancer is estimated to be up to 93%. Unusual genital tract tumours may also occur.
• Patients require lifelong cancer surveillance with prophylactic polypectomy.
• Small bowel obstruction is a frequent complication; up to 70% of individuals require laparotomy for small bowel obstruction by the age of 18 years.