Peutz-Jeghers syndrome

Mucocutaneous melanotic pigmentation and GIT polyps

Genetics

Autosomal dominant, but about 50% are sporadic
Mutation in STK11/LKB1 tumour suppressor on 19p
High degree of penetrance
90% lifetime risk of cancer
Hamartomas - polyps differ histologically from juvenile polyps - overgrowth of smooth muscle (muscularis mucosa), extending into lamina propria

Three or more histologically-confirmed Peutz-Jeghers polyps
Any numer of PJ polyps with a family history of PJS
Characteristic, prominent, mucocutaneous pigmentation with a family history of PJS
Any number of PJS polyps and characteristic prominent mucocutaneous pigmentation

CRC
- 39% lifetime risk
Gastric polyps
- These have a 2-3% malignancy rate
- Seen in about 25% of patients
Small bowel hamartomas (90%)
- Most commonly jejunum and ileum, but 50% also have rectal and colonic lesions
- Can present with intermittent intussusception
- Adenomatous transformation can occur but malignancy is rare
- If resection is required, do endoscopy at the same time to clear upstream and downstream polyps
Pigmented lesions
- Classically 1-2mm brown or black spots in the circumoral region, buccal mucosa, forearms, palms, soles, digits and perianal region
Extracolonic cancers in 50-90% of patients
- Small intestine
- Stomach
- Pancreas - 100x general population
- Ovary
- Lung
- Uterus
- Breast - 45% by age of 70
- Testicular

Small bowel enteroscopy at 10yo - if normal, repeat at 18yo, then at 2-3 year intervals
- Polyps >1cm removed endoscopically
Colonoscopy and gastroscopy starting at 18yo and repeated every 2-3 years
- Remove colon polyps >1cm
Pancreatic screening EUS or MRCP and CA19-9 every 1-2 years starting at age 25-30
Annual testicular examination starting at age 10
Annual pelvic examination and Pap smear starting at age 18
Breast physical exams every 6 months and yearly mammogram and MRI starting at age 25