RESUMEN
X-linked lymphoproliferative syndrome type 2 (XLP2) is a rare genetic primary immunodeficiency disease caused by mutations in the XIAP gene that lead to deficiency of the X-linked inhibitor of apoptosis protein. XLP2 is characterized by dysregulated immune responses and can result in an inflammatory bowel disease (IBD)-like phenotype, a form of monogenic IBD. Patients with XLP2 often succumb to fulminant hemophagocytic lymphohistiocytosis or Epstein-Barr virus infections. Hematopoietic stem cell transplantation (HSCT) is currently the only definitive treatment for XLP2. We report an adolescent with a delayed diagnosis of XLP2 in the setting of severe Crohn's disease diagnosed at age 9 years and recurrent skin infections. He is under evaluation for HSCT. Gastroenterologists must recognize monogenic IBD in patients of all ages with severe disease and signs of an underlying primary immunodeficiency disease. Patients with suspected monogenic IBD should undergo immunologic and genetic analysis at diagnosis to initiate potentially life-saving treatment.
RESUMEN
Peutz-Jeghers syndrome (PJS) is a rare autosomal dominant inherited condition characterized by hamartomatous gastrointestinal polyps, mucocutaneous pigmentation, and a predisposition for malignancy. Most patients with PJS are diagnosed in the second or third decade of life, and commonly have intussusception as a complication. This report describes an unusual case of a 2-year-old male known to have PJS, who had previously developed a small bowel intussusception caused by a polyp requiring a very short segmental small bowel resection. The patient remained asymptomatic several months after the surgery and then presented with acute abdominal discomfort. On abdominal ultrasound, a target sign measuring 2.7 cm was noted in the left upper quadrant of the abdomen, suggesting a small bowel-small bowel intussusception. There was no evidence of intussusception or bowel obstruction otherwise on diagnostic laparoscopy. It was thought that the previous side-to-side anastomosis had mimicked intussusception on the ultrasound examination. A repeat abdominal ultrasound was performed 1 week after the laparoscopy when the patient was asymptomatic. This again demonstrated a target sign identical in appearance to the previous ultrasound and confirmed that the side-to side anastomosis had in fact mimicked intussusception. It is important that the pediatric gastroenterology, radiology, and surgery communities are aware of this ultrasound finding; it could impact the decision on whether to operate emergently. To our knowledge this is the first report describing this unusual scenario in humans.
