Pediatric Small Bowel-Small Bowel Intussusception

  • Etiology: usually transient, is invagination / telescoping of proximal segment of small intestine (intussusceptum) into distal segment of small intestine (intussuscipiens)
  • Imaging: target sign on transverse image / pseudokidney sign on sagittal image that does not involve colon, should be less than ~ 3 cm in transverse diameter, should go away within 5 minutes, never see lymph nodes in intussusceptum
  • Clinical: if not transient consider investigation for pathological lead point

Radiology Cases of Small Bowel-Small Bowel Intussusception

US of transient small bowel intussusception
Transverse greyscale US (upper left) of the left lower quadrant of the abdomen shows a soft tissue mass demonstrating a target sign measuring less than 2 cm in diameter which on transverse color doppler US (upper right) shows normal vascularity. Sagittal greyscale US of the area shows a pseudokidney sign (below). A repeat US 15 minutes later showed the mass was gone.
CT of Meckel's diverticulum causing small bowel obstructin
Axial (above), coronal (lower left) and sagittal (lower right) CT with contrast of the abdomen shows multiple dilated loops of small bowel and a soft tissue mass in the right upper quadrant just beneath the gall bladder that shows the target sign on the sagittal image and the pseudokidney sign on the transverse and coronal images. The soft tissue mass was still present on an US performed 1 hour later.

Surgery Cases of Small Bowel-Small Bowel Intussusception

Surgical image of small bowel - small bowel intussusception due to Non-Hodgkin lymphoma
Laparoscopic surgical image (above) shows the small bowel-small bowel intussusception. Surgical image of the small bowel after reduction of the intussusception (below) shows the serosa is pink-tan and intact with a 1.5 x 0.6 cm puckered, red, firm area that when opened in pathology revealed a 2.6 x 2.0 cm red-pink mass.

Gross Pathology Cases of Small Bowel-Small Bowel Intussusception

Gross pathological image of small bowel - small bowel intussusception due to Burkitt lymphoma
Gross pathological images of the resected segment of intussuscepted small bowel shows on its serosal surface (above) a 2.0 x 1.2 cm irregular, tan-white centrally ulcerated and umbilicated firm area. The opened image of small bowel (below) reveals a 3.4 x 2.9 x 1.2 cm irregular, tan-white, smooth, firm mass which was sectioned to reveal smooth, tan-white, glistening, homogenous cut surfaces.