What is Peutz-Jeghers syndrome (PJS)?

Peutz-Jeghers syndrome (PJS)

Peutz-Jeghers syndrome is one of the many hamartomatous polyposis syndromes affecting the GIT. It presents with a countless number of hamartomatous polyps in the gastrointestinal tract and mucocutaneous pigmentation. It is inherited as an autosomal dominant fashion. The mutation of the STK11 (serine-threonine kinase 11) gene, located on the long arm of chromosome 19, is responsible for PJS.

Features of Peutz-Jeghers syndrome:

• Numerous hamartomatous polyps in the small intestine (most frequent) and colon.
• Melanin pigmentation on the lips & mouth (circumoral in 95% of the patients), hands (in 70% cases), and feet (in 60% cases). The brown buccal pigment is characteristic of Peutz-Jeghers syndrome.
• Except for the mucocutaneous pigmentation, most cases are asymptomatic.
• Sometimes chronic bleeding, anaemia, small bowel obstruction or intussusception may occur.

Complications of Peutz-Jeghers syndrome:

• There is an increased risk of small bowel or colonic adenocarcinoma.
• There are also risks of cancer of the pancreas, lung, testis, ovary, breast and endometrium.

Diagnosis of Peutz-Jeghers syndrome: 

The diagnosis can be made with genetic testing but this may be inconclusive. Diagnosis is usually made considering the main features of the syndrome (requires two of the three following features):

• Small bowel polyposis
• Mucocutaneous pigmentation
• A family history suggesting autosomal dominant inheritance

Management of Peutz-Jeghers syndrome:

• The diagnosed people should perform regular upper GI endoscopy, colonoscopy, small bowel and pancreatic imaging. Balloon enteroscopy may be necessary to reach all the bowel polyps.
• Polyps larger than 1cm in size should be removed (endoscopic polypectomy).
• Bowel resection should be avoided if possible but may be required in patients presenting with gangrenous bowel due to intussusception.
• A testicular examination is essential for men, while women should undergo pelvic examination, cervical smears and regular mammography.
• Asymptomatic relatives of affected patients should also undergo screening.

Sources:

• Davidson's Principles and Practice of Medicine; 23rd Edition; page 829
• Kumar and Clark's clinical medicine, 9th Edition; 403
• Step up to MRCP Review Notes for Part 1 & Part 2 by Dr. Khaled El Magraby 1st Edition (2015); page 330