Case 268.

History A 65-year-old man presented to the emergency department with a 1-week history of constipation, which was associated with increasing abdominal distention and not passing flatus. Four weeks prior to the current admission he had been diagnosed with metastatic primary adenocarcinoma of the appendix. One week ago, he had been hospitalized with small-bowel obstruction, for which he required laparotomy and loop ileostomy. His medical history included basal cell carcinoma, rheumatoid arthritis, and Barrett esophagus. Physical examination revealed a distended abdomen with tenderness at palpation within the right upper quadrant and lower abdomen and reduced bowel sounds at auscultation. Initial plain-film radiography of the abdomen at admission revealed dilated gas-filled small-bowel loops, suggestive of obstruction. His small-bowel obstruction was managed conservatively on this occasion. Nine days after his admission, the patient became unwell and reported a productive cough. He became tachycardic, tachypneic, and hypotensive. Relevant blood tests at this stage revealed a C-reactive protein level of 206 mg/L (normal range, 0-10 mg/L), a white blood cell count of 24.5 × 109 /L (normal range, [4.0-11.0] × 109 /L), a red blood cell count of 3.39 × 1012 /L (normal range, [4.5-5.5] × 1012 /L), a hemoglobin level of 93 g/L (normal range, 130-170 g/L), and a hematocrit level of 0.27 (normal range, 0.4-0.5). CT of the abdomen and pelvis with intravenous contrast material (100 mL Omnipaque 350; GE Healthcare, Oslo, Norway) was performed ( Figs 1 , 2 ). Figure 1a: (a) Axial and (b) curved reformatted contrast-enhanced CT images of the upper abdomen. Figure 1b: (a) Axial and (b) curved reformatted contrast-enhanced CT images of the upper abdomen. Figure 2a: (a) Axial and (b) coronal contrast-enhanced CT images of the upper abdomen obtained 12 days before the CT images shown in Figures 1a and 1b , respectively. Figure 2b: (a) Axial and (b) coronal contrast-enhanced CT images of the upper abdomen obtained 12 days before the CT images shown in Figures 1a and 1b , respectively.