Teaching Case

A 59-year-old male presented with sudden onset of abdominal pain and nausea lasting for 6 hours. He had a history of hypertension and prior alcohol abuse. On physical examination, a painful mass was palpated in the right upper quadrant of the abdomen. Blood tests were unremarkable.

A contrast-enhanced abdominal CT scan in the portal-venous phase was performed. The scout image showed a dilated air-filled colon loop in the right upper quadrant suggestive of colonic interposition between the liver and right hemidiaphragm – the so-called Chilaiditi’s sign (Figure 1). CT reconstructions revealed a distended caecum in an abnormal location anterolateral to the right hepatic lobe causing displacement of the liver (Figure 2a). There was torsion of the caecum around its mesentery with a whirl sign on the right side of the abdomen (Figures 2b and 2c). A small amount of free intraperitoneal fluid was found. There was no intraperitoneal free air. The final diagnosis was caecal volvulus with associated hepatodiaphragmatic interposition of the caecum. The patient underwent laparotomy, and a right hemicolectomy with an ileocolic anastomosis was performed.

Intestinal volvulus derives from a torsion of the bowel around its mesentery that often results in a closed-loop obstruction. Narrowing of the intestinal lumen and mesenteric vessels at the point of rotation causes bowel distension, which may be complicated by ischemia, necrosis, and perforation [1]. Caecal volvulus is a relatively rare disease accounting for 1–3% of intestinal obstructions and 10–40% of colonic volvulus [2,3]. It is thought to develop primarily due to an abnormal fusion of the mesentery of the caecum and ascending colon with the posterior parietal peritoneum leading to increased mobility of the caecum [3]. Patients with caecal volvulus usually present with abdominal pain, bowel distension, constipation, and vomiting [4]. Although caecal volvulus can often be correctly diagnosed using plain abdominal radiographs, abdominal CT is the imaging modality of choice, allowing for the identification of associated complications and for surgical planning [1,5]. Surgical resection of the caecum by a right hemicolectomy is the favoured treatment option both in patients with gangrenous and viable bowel [2].

Hepatodiaphragmatic interposition of the colon (Chilaiditi’s sign) is a rare anomaly with a reported incidence ranging from 0.25–2.8 ‰ in the general population [6], while Chilaiditi syndrome is a medical condition occurring when Chilaiditi’s sign is accompanied by clinical symptoms [7]. Chilaiditi’s sign is associated with anatomical variants in the liver, diaphragm and intestine, including abnormal fixation of the colon due to laxity or elongation of its suspensory ligaments [7]. Both congenital malposition of the intestines and agenesis of the right hepatic lobe, or acquired aetiologies such as phrenic nerve injury, chronic lung disease, cirrhosis, and obesity may increase the risk of Chilaiditi’s sign [8]. Important differential diagnoses of Chilaiditi’s sign are subphrenic abscess and pneumoperitoneum [7].

Volvulus of the caecum, sigmoid or transverse colon is a rare complication of Chilaiditi syndrome with only a few reported cases [6–10]. In our patient, the clinical presentation, CT imaging and surgical findings were consistent with an acute abdomen due to a caecal volvulus causing Chilaiditi’s sign. There was no prior imaging or gastrointestinal symptoms to suggest, that the patient had Chilaiditi’s sign or Chilaiditi syndrome before the acute presentation of caecal volvulus.

In conclusion, our case emphasizes that Chilaiditi’s sign may rarely be found in association with caecal volvulus.

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