Hospital: Hospital Universitario Ramón y Cajal.
Aut@r o Autores: P. Marazuela García, C. Picón Serrano, J. Blanc Molina, A. López-Frias López-Jurado, B. Alba Pérez, F. González Tello.
25 year old woman attending the emergency room because of three days with nausea and vomiting (alimentary and bilious content). Increase of depositional frequency with hematic feces. Slight abdominal distension and increased hydro-acoustic noises. Diffuse abdominal colic pain, mainly in both iliac fossae. No fever. No voiding syndrome neither hematuria. Pregnancy test negative. No other personal background of interest. In the laboratory results, highlights exclusively mild PCR rise (16.4 mg/L) and leukocytosis (13.1 10^3/µL). IMAGE FINDINGS: A- Exploring the right hypochondrium with a low frequency convex probe, we identify the “target sign”, characteristic of intestinal intussusception. This image is formed by concentric alternating echogenic and hypoechogenic bands. The echogenic bands are formed by mucosa and muscularis whereas the submucosa is responsible for the hypoechoic bands. In the middle of the target we distinguish a very hiperechogenic nodular image (arrow). B, C. Oblique coronal reconstructions of abdominal IVC CT, show the correlation with the target sign in the ultrasound. The hiperechogenic image in the middle of the target (arrow) consists on a small bowel lipoma. D. In the oblique sagittal reconstruction we can appreciate the length of the intussuscepted segment (about X cm). We also recognize expanded ileum loops with hydro-aerials levels.
Intestinal intussusception is rare in adults, accounting for 1 to 5 percent of mechanical bowel obstructions. About 80–90% are secondary to an underlying pathology, with approximately 65% due to benign or malignant neoplasm. There are three types according to location, entero-enteric, ileo-colic and colo-colic, which is important because the etiology is quite different. When the leading point originates in the small bowel it is usually secondary to benign lesions (lipoma, leiomyioma…) adhesions, Meckel’s diverticulum, etc. However when the leading point arises from the large bowel it is more common to have a malignant etiology (adenocarcinoma and lymphoma). Apart from the etiology, CT is useful to distinguish signs suggesting self-limiting intussusception versus surgical cases. The most important is the length of the intussuscepted segment. When greater than 3.5 cm it is suggestive of surgical correction. Other signs such as known malignancy, age, and the presence of infiltration, edema, or ascites are against self-limiting evolution.
Despite of being rare, intestinal intussusception in adult age shows the same classic “target sign” which is identified in children. This image can be recognized with the ultrasound, and complementary CT gives us information about the etiology and the prognosis factors.
- Gayer G, Zissin R, Apter S, Papa M, Hertz M. Adult intussusception—a CT diagnosis. The British Journal of Radiology. February 2002,75(890):185-90. Available in: http://www.birpublications.org/doi/10.1259/bjr.75.890.750185 - Lvoff N, Breiman RS, Coakle