Purpose: To determine the clinical presentation in cases of adult intussusception demonstrated at computed tomography (CT) or magnetic resonance (MR) imaging and to correlate the imaging appearance with clinical diagnosis.
Materials and methods: Retrospective review of CT and MR images and clinical records of all patients with an intussusception demonstrated on CT or MR images from January 1, 1991, through April 30, 1998.
Results: Thirty-three patients had one or more intussusceptions demonstrated on CT (n = 30) or MR (n = 3) images. Twenty-nine patients had enteroenteric intussusceptions, and four had intussusceptions involving the colon. Ten patients (30%) had a neoplastic lead point, including all four of the intussusceptions involving the colon (benign mass, n = 3; malignant mass, n = 7). In 23 cases (70%), no neoplastic lead point was identified. A variety of causes were implicated in these cases, with 16 cases (48%) classified as idiopathic. Enteric intussusceptions in the nonneoplastic group were shorter in length (median, 4 vs 10.8 cm; P = .002), smaller in diameter (median, 3 vs 4 cm; P = .002), and less likely to be associated with obstruction (4.3% vs 50%; P = .02).
Conclusion: Less than one-third of adult intussusceptions demonstrated at CT or MR imaging were caused by a neoplastic lead point. Almost half of adult cases in this series were idiopathic.