Peutz–Jeghers syndrome (often abbreviated PJS) is an autosomal dominant genetic disorder characterized by the development of benign hamartomatous polyps in the gastrointestinal tract and hyperpigmented macules on the lips and oral mucosa (melanosis).

[8] Patients with the syndrome also have an increased risk of developing carcinomas of the liver, lungs, breast, ovaries, uterus, testes, and other organs.

[8] Dark blue, brown, and black pigmented mucocutaneous macules, are present in over 95 percent of individuals with Peutz–Jeghers syndrome.

[8] Complications associated with Peutz–Jeghers syndrome include obstruction and intussusception, which occur in up to 69 percent of patients, typically first between the ages of 6 and 18, though surveillance for them is controversial.

It is inherited in an autosomal dominant pattern, which means that anyone who has PJS has a 50% chance of passing the disease on to their offspring.

[citation needed] Peutz–Jeghers syndrome is rare and studies typically include only a small number of patients.

The oral findings are consistent with other conditions, such as Addison's disease and McCune–Albright syndrome, and these should be included in the differential diagnosis.

[15] Some suggestions for surveillance for cancer include the following:[citation needed] Follow-up care should be supervised by a physician familiar with Peutz–Jeghers syndrome.

[citation needed] First described in a published case report in 1921 by Jan Peutz (1886–1957), a Dutch Internist, it was later formalized into the syndrome by American physicians at Boston City Hospital, Harold Joseph Jeghers (1904–1990) and Kermit Harry Katz (1914–2003), and Victor Almon McKusick (1921–2008) in 1949 and published in the New England Journal of Medicine.