Intestinal malrotation (IM) is an abnormality of midgut rotation during embryonic development. In most cases of IM, patients exhibit symptoms of a midgut volvulus or intestinal obstruction in childhood. It is rarely found in adulthood, and most are discovered during testing or surgery for other comorbidities (1). However, a preoperative understanding of such an anatomical abnormality is crucial to ensure surgical safety. Here, we report a rare laparoscopic colectomy for cecal cancer with intestinal malrotation that was diagnosed preoperatively on imaging studies. Using this preoperative information, we safely performed laparoscopic surgery using a suitable approach. The SCARE Checklist has been completed by the authors for this case report (2). The Ethical committee of our institute approved (No.15144-6) this study and written informed consent was obtained from the patient for the publication of this case report and any accompanying images.

An 80-year-old woman was admitted to our hospital complaining of abdominal pain and dyspepsia. She had no appreciable medical and surgical history. Colonoscopy revealed a type 3 cancer covering the entire circumference of the cecum (Figure 1). Examination of the biopsy specimens revealed well-differentiated tubular adenocarcinoma.

Computed tomography (CT) revealed a tumor measuring approximately 47 mm in diameter in the cecum (Figure 2A). The cecum was located at the midline of the abdominal cavity. One lymph node at the back of the tumor was swollen to a diameter of 10 mm (Figure 2B). There was one liver metastasis, 32 mm in diameter, in the right posterior inferior segment (Figure 2C), and three peritoneal disseminations localized in the lower abdomen. Positron emission tomography–CT showed abnormal accumulation in the lesions (Figure 3A-D). The duodenum did not cross the midline and the ileocolic vein ran to the left (Figure 4). Laboratory tests revealed elevated CEA (13 ng/ml) and CA 19-9 (112.8 U/ml) levels. She was clinically diagnosed with stage IVc cecal cancer T4a N1 M1c (H1P1) complicated by intestinal malrotation (IM). The patient underwent laparoscopic ileocecal and disseminated lesion resections with D3 lymph node dissection. Two disseminated lesions and one liver metastasis (S6) were visualized intraoperatively.

The ascending colon and cecum were not fixed to the retroperitoneum. The duodenum lacked the second, third, and fourth portions and the small bowel was located on the left and right sides of the abdominal cavity. The ascending colon showed adhesions with the transverse colon, and the cecum adhered to the sigmoid colon (Figure 5A). The mesentery was shortened by adhesions; therefore, the ileocolic vein could not be identified. All adhesions were released, and the cecum was pulled to the right lower abdomen, close to its normal position (Figure 5B). The ileocolic artery/vein (ICA/V) was separated from the superior mesenteric artery/vein (SMA/V) at its root. The operative time was 177 min, with minimal blood loss.

The patient was readmitted to the hospital because of reduced oral intake, but was able to be discharged 14 days after surgery, and was followed up at the outpatient clinic. The pathological diagnosis was pathological T4a(SE) N2aM1 Stage IV.

IM is an abnormality of midgut rotation during embryonic development. It is usually diagnosed as a midgut volvulus or intestinal obstruction in childhood and is rarely found in adulthood (1).

Nishijima et al. reported the following types: a) non-rotation, b) incomplete rotation, and c) incomplete fixation (3). In general, most cases in adulthood are of the non-rotation type, which is asymptomatic (4); however, this case was of the incomplete rotation type. Because it is mostly asymptomatic, it is most often discovered during testing or surgery for other comorbidities in adults. Imaging findings indicated that the small intestine was on the right side of the abdominal cavity, with the duodenum not crossing the midline (5). The SMV exists on the left side of the SMA (SMV rotation sign) (6,7), and in this case, the SMV was laid on the left ventral aspect of the SMA on CT.

Colorectal cancer with IM is rare (8), but many reported cases of malignant tumors are associated with right colon cancer. Repeated chronic inflammation of the oral colon is thought to be due to chronic obstruction caused by IM and vascular ischemia (9). Since 2000, 49 cases of colorectal cancer have been recognized with IM as a complication (Table I). Among these 49 patients, 41 cases of right-sided colon cancer have been reported, and most were of the non-rotation type. In recent years, many patients have been diagnosed with IM preoperatively, and the rate of preoperative diagnosis seems to be increasing in accordance with improvements in diagnostic imaging capabilities, such as three-dimensional CT scans.

Laparoscopic surgery is superior to open surgery in terms of securing the field of view in a narrow space, providing a magnifying effect, and minimal invasiveness. In addition, multiple randomized control trials investigating long-term oncological results have shown noninferior results (10,11), and this is now a common surgical method in colorectal cancer surgery. However, it has a limited field of view and is inferior in terms of grasping the overall anatomy, which may be disadvantageous in cases of anatomical abnormalities, such as in the present case. To compensate for such issues, it is important to understand the anatomy using preoperative imaging and select an appropriate approach.

In this case, the preoperative three-dimensional CT scan showed IM, and although the ileal blood vessels ran to the left, it was confirmed that they branched from the SMA/V as usual and that there was no branching malformation. Adhesion is observed in many cases, including the present one, possibly because of chronic inflammation. First, by firmly detaching the adhesions and releasing the shortening of the mesocolic ligament, the ileocecal region of the present case was repositioned to the lower right abdomen, resembling the standard anatomical positional relation. As a result, the ileal arteriovenous root was identified accurately and safely, and dissection was performed sufficiently.

The Authors declare that they have no competing interests in relation to this study.

R.M. and N.M. conceived and performed the operation. Data collection was performed by R.M. and N.M. The first draft of the manuscript was written by R.M. and N.M. T.I., S.N., Y.S., T.H., A.H., T.O., H.T, M.T., Y.K., M.U., Y.D., and H.E. commented on previous versions of the manuscript. All Authors have read and approved the final manuscript.

No funding was received for this study.