Introduction/Background Colorectal carcinoma (CRC) is commonly found in adults. CRC in the paediatric population is extremely rare.

Paediatric patients with CRC present with non-specific symptoms (abdominal pain, obstructive symptoms, anaemia) and may have an abdominal mass – similar to the presentation in adults.

Primary GI malignancies constitute ~2% of paediatric neoplasms. On the other hand, paediatric CRC comprises a small proportion of all CRC. Diagnosis of CRC in the paediatric population is usually delayed due to its rarity and therefore low index of suspicion. CRC in children can be associated with Polyposis Syndromes and inflammatory bowel disease (IBD). Sporadic CRC in children is rare.

We report a case of mucinous adenocarcinoma of the colon in a 17-year old female who presented with abdominal pain, altered bowel habit, anaemia and developed bowel perforation while awaiting colonoscopy. Diagnosis was confirmed on histology of resected caecum and ascending colon.

Case report A 17-year old adolescent girl was admitted under general paediatric team with abdominal pain, blood in stool, feeling tired, possible low-grade fever. She was noted to have severe anaemia (Hb 47 g/L); other blood results unremarkable. She was treated with intravenous antibiotics and received blood transfusion. Her abdominal pain and diarrhoea improved. There is no family history of any bowel disorder. Her stool sample culture was negative. Calprotectin was >1000 microgram/gm raising suspicion of IBD. Ultrasound abdomen showed ‘some faecal loading in caecum and ascending colon’, otherwise unremarkable. She was discharged with plan for colonoscopy within 4 weeks.

Three weeks later she re-attended with acute severe abdominal pain and was re-admitted under gastroenterology team. She had an extremely tender abdomen with guarding in right iliac fossa. CT abdomen showed localised perforation in ascending colon with a mass and extensive fat stranding. She underwent an emergency laparotomy, right hemicolectomy with ileostomy formation.

Results The details of the resected tumour are given in table I below.

She was referred to Adult Colorectal Surgical and Oncology team and was started on adjuvant chemotherapy following MDT discussion.

Discussion Diagnosis of CRC in paediatric patients remains an incidental finding due to nonspecific symptoms and low level of suspicion. Therefore, it usually gets diagnosed at advanced stage and bears poor prognosis. Although CRC is more common in older adults its incidence is increasing in younger age group including <20-year olds. Mucinous adenocarcinoma comprises >50% of all paediatric CRC and has a poor prognosis.

Conclusion Though CRC presents with non-specific symptoms in children and adolescents, this case is presented to raise awareness of its possibility. Input from the Adult Colorectal MDT is recommended for further management.