Anatomical challenge: a rare coexistence of caecal cancer and isolated duodenal malrotation

Background

Intestinal malrotation is a congenital anomaly found in 1 to 200–6000 births.1 2 Most of the cases are discovered and treated within 1 year of birth, showing typical symptoms such as vomiting, caused due to volvulus or stricture.2 Some adult cases present with symptoms related to chronic intestinal passage failure or volvulus, while others are discovered incidentally during abdominal surgery for other diseases, often confusing surgeons because of the anatomical abnormality.2 3

In this report, we present a rare combination of caecal cancer with isolated duodenal malrotation, a subtype of intestinal incomplete malrotation. The malrotation was incidentally found during the operation and required careful adhesiolysis and resection because of the anatomical complexity.

Case presentation

A woman in her 80s (150 cm and 40 kg) was referred to the emergency department of our hospital with abdominal pain, which had worsened over the last 2 days. Her general condition was stable, while the abdominal examination revealed mild to moderate lower abdominal pain without panperitoneal irritation. The patient had no previous history of chronic abdominal symptoms.

Investigations

Contrast-enhanced CT revealed stricture of the ileocaecal valve, with ileal dilation (figure 1A,B). Laboratory results showed no inflammation but revealed tumour marker elevation: white cell count 6300/µL, C reactive protein 0.37 mg/dL (reference range 0–0.14), haemoglobin 13.1 g/L (reference range 11.3–14.9), blood urea nitrogen 12.0 mg/dL (reference range 8–20), creatinine 0.78 mg/dL (reference range 0.46–0.79) and carcinoembryonic antigen 10.2 ng/mL (reference range 0–5.0).

Treatment

After emergent admission, the patient underwent transnasal ileus tube placement for decompression of intestine (figure 2A,B). After efficient decompression, laparoscopic ileocaecal resection was performed. Intraoperative findings showed abnormality of the midgut, duodenum and intestine. The edge of duodenum was found near the root of superior mesenteric artery (SMA), running caudally without passing Treitz ligament (figure 3A–D). Lymphatic resection was started by resecting ileocaecal artery (ICA); however, duodenum or pancreas was not found at the dorsal space of ICA. By revealing superior mesenteric venous (SMV) and a branch of ileocaecal vein, D3 lymphatic resection was completed. At this moment, a loose layer was revealed, which was the fusion fascia between colonic mesentery and intestinal mesentery. Tracing this layer cranially, first and second part of duodenum was identified (figure 4A,B). A lateral approach showed duodenum running dorsally, covered with ascending colon, colonic mesentery and Ladd’s bands (figure 5A,B). The adhesiolysis of this part and resection of the Ladd’s bands enabled identification of the complete duodenum and mobilisation of ileocaecal colon (figure 5C,D). After resecting the ileocaecal part outside the body, side-to-side anastomosis was performed. The operative time was 173 min, and blood loss was 17 mL.

Outcome and follow-up

The postoperative X-ray showed a straightened duodenum (figure 6). The ileus tube was removed on postoperative day (POD) 2, and oral intake was started on POD 3. The postoperative course was uneventful, and the patient was discharged on POD 9. In the pathological findings, there was a stricture of the ileocaecal valve with T3 adenocarcinoma, moderately differentiated, N1 (metastatic paracolonic lymph node); stage IIIB (the UICC TNM staging, eighth edition).

Capecitabine was administrated as adjuvant chemotherapy. After 6 months of surgery, there were no abdominal symptoms or cancer recurrence.