A63-year old woman presented with a 4-day history of watery diarrhoea that was preceded by acute constipation. This was associated with intermittent colicky abdominal pain and one episode of fresh rectal bleeding on the previous day. Past history included haemorrhoids, cholecystectomy and reflux disease with no significant family history of cancer. She was seen in the accident and emergency department with a mass in right iliac fossa (RIF), which was managed as scabylous mass owing to the history of constipation. The next day, the woman came back with continued symptoms. On this occasion, she had a firm, mobile mass, now palpable in the left hypochondrium associated with abdominal distension. Rectal examination revealed an empty rectum. Haematological and biochemical tests including tumour markers were essentially normal. Plain X-ray of the abdomen revealed a partial small bowel obstruction and the patient was commenced on conservative management. The following day, although her symptoms resolved, the mobile abdominal mass was still persistent but now palpable in the RIF. An ultrasound examination of the abdomen and pelvis showed ‘a pseudo-kidney’ sign in the RIF (Figure 1). An unprepared contrast enema revealed a possible neoplastic lesion at the splenic flexure (Figure 2). Helical computed tomography showed a ‘bowel within bowel’ appearance in the left hypochondrium with proximally-dilated small bowel loops (Figure 3). She underwent a laparotomy, which showed a mobile, ileocaecal tumour with intussusception reaching the splenic flexure. There was no evidence of disseminated disease. An extended right hemicolectomy with en-bloc resection of the intussuscepting mass was performed. She had an uneventful postoperative period. Pathological examination of the resected specimen revealed a 4.0 cm × 4.5 cm × 3.0 cm nodular tumour of the ileocaecal valve with intussusception of a 6.0 cm length of terminal ileum. Histological examination showed a moderately well differentiated adenocarcinoma with clear resection margins (Figure 4). There was no nodal or vascular invasion. Pathological staging of the tumour was Dukes' A, T2 (tumor confined to bowel wall), N0 (no tumor deposit in 11 lymph node harvested) (0/11), M0 (no distance metastasis).