Autosomal dominant syndrome.
Median age of onset is 11 years.
Associated with multiple gastrointestinal hamartomatous polyps and mucocutaneous hyperpigmentation.
More than 50% will have heterozygous loss of -function mutation in the LKB1/STK11 gene.
Hyperpigmentation takes the form of macules around the mouth, eyes, nostrils, buccal mucosa, palms, and genital and perianal regions.
They have increased risk of several cancers including colon, pancreas, breast, lung, gonads and uterus.
Histologic examination demonstrates a characteristic arborizing network of connective tissue, smooth muscle, lamina propria, and glands lined by normal-appearing intestinal epithelium.
The arborization and presence of smooth muscle intermixed with lamina propria are helpful in distinguishing polyps of Peutz-Jeghers syndrome from juvenile polyps.
