Extremely young case of small bowel intussusception due to Peutz–Jeghers syndrome with nonsense mutation of STK11

Intussusception is a frequent and severe complication of Peutz–Jeghers syndrome (PJS). We herein present the case of a 3-year-old girl who experienced jejuno-jejunal intussusception due to PJS polyps. Despite no apparent family history of PJS, she had exhibited mucocutaneous pigmentation since infancy and recurrent abdominal pain and vomiting from 2 years of age. Segmental resection of the jejunum during emergency laparotomy for the intussusception revealed multiple hamartomatous polyps. Genetic analysis uncovered a germline nonsense mutation of c.247A>T in exon 1 of serine/threonine kinase 11 (STK11). Biannual follow-up surveillance for polyps by esophagogastroduodenoscopy, colonoscopy, and small bowel capsule endoscopy is ongoing. Reports describing the clinical and genetic features of extremely young PJS with intussusceptions are rare, although a literature review of STK11 germline mutations revealed several other pediatric cases of complicating intussusception at ≤ 8 years old. Considering the recent advances in surveillance and treatment options for the small bowel, earlier management of symptomatic children with PJS may be warranted to avoid surgical emergency.