The objectives were to review adult intussusception, its diagnosis, and its treatment. Adult intussusception represents 1% of all bowel obstructions, 5% of all intussusceptions, and 0.003%-0.02% of all hospital admissions. Intussusception is a different entity in adults than it is in children. The records of all patients 18 years and older with the postoperative diagnosis of intussusception at the Massachusetts General Hospital during the years 1964 through 1993 were reviewed retrospectively. The 58 patients were divided into those with benign enteric, malignant enteric, benign colonic, and malignant colonic lesions associated with their intussusception. The diagnosis and treatment of each were reviewed. In 30 years at the Massachusetts General Hospital, there are 58 cases of surgically proven adult intussusception. The patients' mean age was 54.4 years. Most patients presented with symptoms consistent with bowel obstruction. There were 44 enteric and 14 colonic intussusceptions. Ninety-three percent of the intussusceptions were associated with a pathologic lesion. Forty-eight percent of the enteric lesions were malignant and 52% were benign. Forty-three percent of the colonic lesions were malignant and 57% were benign. Intussusception occurs rarely in adults. It presents with a variety of acute, intermittent, and chronic symptoms, thus making its preoperative diagnosis difficult. Computed tomography scanning proved to be the most useful diagnostic radiologic method. The diagnosis and treatment of adult intussusception are surgical. Surgical resection of the intussusception without reduction is the preferred treatment in adults, as almost half of both colonic and enteric intussusceptions are associated with malignancy.

The preoperative diagnosis of adult intussusceptions (AIs) remains difficult, and the assessment of the radiological methods has been evaluated very little in the literature. The aim of this study was to evaluate the interest of the different imaging modalities for the preoperative diagnosis of AI and describe causes of AI. Consecutive patients of 15 years and older with the postoperative diagnosis of intussusception from 1979 to 2004 were reviewed retrospectively for this multicentric study. Data concerning clinical considerations, morphological examinations, surgical procedure, histological conclusions, mortality rate and recurrence were analysed. Forty-four patients with documented intussusception were included. The mean age was 51 years (15-93 years). The preoperative diagnosis of intussusception was made in 52% of the cases. The sensitivities of the different radiological methods were abdominal ultrasounds (35%), upper gastrointestinal barium study (33%), abdominal computed tomography (CT) (58%) and barium enema (73%). An organic lesion was identified in 95% of the cases. There was 29 enteric and 15 colonic (including appendicular) intussusceptions. Thirty-seven percent of the enteric lesions were malignant, and a bit less than 50% of them were metastatic melanomas. The benign enteric lesions were Meckel's diverticulum and Peutz-Jeghers syndrome in half of the cases. Fifty-eight percent of the pure colonic lesions (excluding appendix) were malignant, and 85% of them were primary adenocarcinomas. The benign colonic lesions were lipomas in 80% of the cases. All patients, except one, had a surgical treatment, and 13 of them had a complete reduction of the intussusception before resection. The mortality rate was 16% and recurrence occurred in three patients; two of them had a Peutz-Jeghers syndrome. Intussusception rarely occurs in adults, but nearly half of their causes are malignant. The CT scan is a helpful examination for enteric intussusceptions whether barium enema seems to be the most performing method for colonic lesions. Surgery is the recommended treatment, with or without a primary reduction of the intussusception. During the surgical procedure, this reduction can lead to a more limited bowel resection.

Intussusception is relatively rare in the adult population and differs substantially from pediatric intussusception. Most adult intussusceptions identified at surgery are caused by a definable structural lesion, a substantial proportion of which are malignant, particularly in the colon. Small bowel intussusceptions, however, have a lower prevalence of malignancy. Diagnosis of adult intussusception can be made reliably with noninvasive imaging techniques. CT is now widely regarded as the modality of choice for diagnosing intussusception in adults, but ultrasound and MR imaging have also been used effectively. Determination of the presence of a malignant lead point remains problematic because an edematous or hemorrhagic intussuscipiens may mimic a mass on each modality. Markers for bowel viability have been described but are not precise. Treatment of the persistent symptomatic intussusception in which neoplasia is suspected is surgical, and preoperative reduction is contraindicated. Transient relatively asymptomatic enteric intussusceptions discovered by imaging may not require intervention.