Colonic tumour presenting as discrete upper abdominal mass.

To cite: Hamilton B, Pang CL, Adlan T. BMJ Case Rep Published online: [please include Day Month Year] doi:10.1136/bcr-2015211311 DESCRIPTION A 72-year-old retired museum guide presented with a discrete lump in the right upper quadrant of his abdomen, which he noticed after feeling a pull in his abdomen while heavy lifting several days prior. The lump was firm, tender and warm with overlying erythema, and was reducible on palpation and lying flat. He had no previous abdominal surgery and was clinically well. He had microcytic anaemia and C reactive protein of 127 mg/dL. The clinical differential was spontaneous hernia, abscess or haematoma. An abdominal ultrasound scan (USS) revealed a mobile lesion of mixed echogenicity that resembled a bowel sonographic signature (figure 1). The base of the lesion could not be identified; it appeared to originate from the peritoneum (figure 2), suggestive of a hernia. A subsequent CT demonstrated a segregated 7 cm×6 cm anterior abdominal wall collection, the base of which abutted the peritoneum. Immediately beneath, there was focal mural thickening at the hepatic flexure adhering to the collection (figure 3). The patient underwent emergency laparotomy, revealing a complex tumour arising from the hepatic flexure with associated enterocutaneous fistula and superficial collection. This was further reported as a moderately differentiated Duke’s B adenocarcinoma pT4N0, and the patient went on to receive adjuvant chemotherapy. This patient had an unusual presentation that was initially suggestive of an abdominal hernia, and, without imaging beyond the initial USS, he was at high risk of perforation, infection or metastasis. 3