Peutz-Jeghers syndrome involves a mutation in a tumor suppressor gene and is associated with malignant tumors arising at a young age.


Inheritance: autosomal dominant


Gene affected: LKB1 (STK11) on chromosome 19p13.3


Clinical findings:

(1) pigmentation of buccal mucous membranes, lips and perioral area

(2) pigmentation of fingers and toes


Hamartomatous polyps:

(1) hamartomatous polyps all along the GI tract, often multiple

(2) hamartomatous polyps in the nasopharynx or bronchial mucosa

(3) hamartomatous polyps in the biliary tract

(4) hamartomatous polyps in the urinary bladder


Malignant tumors that may arise from the polyps:

(1) small bowel adenocarcinoma

(2) adenocarcinoma in the biliary tract

(3) colorectal adenocarcinoma


Other tumors:

(1) bronchogenic carcinoma

(2) pancreatic adenocarcinoma

(3) thyroid tumors

(4) ovarian sex cord tumor with annular tubules

(5) testicular sex cord or Sertoli cell tumors

(6) infiltrating ductal carcinoma of the breast

(7) cervical adenocarcinoma

(8) bladder cancer


Other complications:

(1) intussusception

(2) gastrointestinal hemorrhage with iron deficiency

(3) precocious puberty (associated with gonadal tumors)

(4) protein losing enteropathy

(5) clubbing of the fingers


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