What is the skin manifestation commonly seen in patients with Peutz-Jeghers syndrome?

Peutz-Jeghers syndrome is a genetic condition characterized by the development of hamartomatous intestinal polyps and a predisposition to various types of cancers. One of the hallmark features of this syndrome is mucocutaneous hyperpigmentation, which typically presents as dark brown to blue-gray macules. These lesions are commonly found on the lips, buccal mucosa, and may also appear around the eyes, nostrils, and on the hands and feet.

The presence of these pigmented lesions is significant for diagnosis, as they occur in childhood or adolescence and are often accompanied by gastrointestinal symptoms due to the polyps. The hyperpigmentation in Peutz-Jeghers syndrome is distinct from other skin manifestations, such as freckling or moles, which do not have the same association with the syndrome's clinical spectrum. The pigmentation seen in Peutz-Jeghers is specifically linked with the condition's genetic background and is not simply a benign or cosmetic issue, making it an important clinical clue for identifying patients who may be at risk for associated malignancies.