Ileocolic intussusception as a presenting feature of cecal carcinoma

Clinical History

The case describes the presentation of a cecal carcinoma with small bowel obstruction due to an ileocolic intussusception

Imaging Findings

The patient, a previously well 67y female, presented acutely with abdominal pain, distension, constipation and vomiting. Initial radiographic investigation was with a supine abdominal radiograph which offered no specific diagnosis (Figure 1). Ultrasound was next performed which suggested intussusception (Figure 2), and on the strength of this, she proceeded to CT of the abdomen and pelvis with intravenous contrast (Figure 3) prior to laparotomy.

Discussion

Intussusception occurs when a segment of bowel (the intussusceptum) invaginates and comes to like within a segment of more distal bowel (the intussuscipiens). Disturbance of normal peristalsis by a focal abnormality within the bowel wall is the usual underlying cause. It is particulary common in children aged 6 months to 2 years, and an acute presentation with crying, drawing up of the legs and a bloody ('redcurrant jelly') stool is classic. In this age hyperplasia of lymphoid tissue in the bowel wall due to mild intercurrent illness is the most usual cause of the precipitating bowel wall abnormality. Because the bowel wall abnormality is the result of a self-limiting process, a conservative approach may be justified, with an attempt to reduce the intussusception with an air enema. Intussusception in the adult population presents a different clinical scenario. The abnormality in the bowel wall is usually neoplastic (either benign or malignant) [1], and therefore surgical management is usually required, with the urgency of operation determined by the clinical state of the patient. The imaging features of this case are typical. Ultrasound revealed a mass which had a 'target' appearance axially and 'pseudokidney' in longitudinal section - it is the mesenteric fat drawn into the lumen of the intussuscipiens that simulates the sonographic appearances of the fat of the renal sinus. The ultrasound also demonstrated intestinal obstruction proximal to the intussusception with multiple fluid filled dilated small bowel loops. Although the patient was clinically obstructed these loops were not visible on the plain abdominal radiograph, due to the absence of air within the small bowel lumen. The rationale for proceeding to CT prior to surgery in this case was twofold. The first reason was to confirm the ultrasound diagnosis and define more clearly the position of the lesion. Secondly, since intussusception in this age group is quite likely to be the manifestation of a malignancy, CT provides additional information in terms of tumor staging. The CT appearances in this case are again typical, with mesenteric fat and vessels drawn in into the intussuscipiens to produce pseudokidney and target appearances. No evidence of metastatic or synchonous disease was seen, and the operative management was a right hemicolectomy. The gross specimen is shown in Figure 4. No macroscopic tumour was evident, but sectioning of the right colon demonstrated adenocarcinoma.

Differential Diagnosis List

Final Diagnosis

Ileocolic intussusception due to cecal carcinoma

URL:	https://www.eurorad.org/case/5688
DOI:	10.1594/EURORAD/CASE.5688
ISSN:	1563-4086