Peutz-Jegers syndrome (PJS)

Peutz-Jegers syndrome (PJS) is a rare hereditary disease characterized bymelanocytic macules of the lips, gastrointestinal hamartomatous polyps andan increased risk for many classes of cancer. The serine/threonine kinase LKB1(also designated STK11) has been identified as the gene mutated in PJS. LKB1activity increases upon the binding of a regulatory complex consisting of theSte20-related adaptor α (STRAD α) pseudo kinase and the calcium-bindingprotein 39 (MO25 α).

STRAD determines the subcellular localization of LKB1by initiating its translocation from the nucleus to the cytoplasm, thus regu-lating the tumor suppressor activity of LKB1. The gene encoding humanSTRAD maps to chromosome 17q23.3.

48-year-old woman with Peutz-Jeghers syndrome who presented with duodenojejunal intussusception caused by hamartomatous polyps. Radiograph obtained during small-bowel follow-through shows dilated proximal jejunum. Contrast material has entered space between intussusceptum and intussuscipiens, causing coiled spring appearance (arrows), a sign of intussusception. Note several polypoid lesions (arrowheads) in gastric antrum and jejunum. Operative findings confirmed two intussusceptions of duodenojejunal and ileocecal type caused by hamartomatous polyps. Open polypectomy was performed.