ABSTRACT

Malrotation is an anomaly that occurs when the embryological middle bowel, or ‘midgut’, rotates around the superior mesenteric artery and ends with opposite fixation to the peritoneum. There are many causes of left lower quadrant abdominal pain, the main reasons being diverticulitis, hernias, neoplasms, sigmoid colon perforations, testicular torsions, urinary pathologies, and gynecological pathologies. Although left lower quadrant abdominal pain is associated with the diagnosis of acute appendicitis in patients with malrotation, a known history of malrotation is helpful for diagnosis. In this case report, a patient who admitted with left lower quadrant abdominal pain and was diagnosed as malrotation and acute appendicitis is presented.

Introduction

Acute appendicitis is one of the leading causes of abdominal pain in patients presenting to emergency services, and appendectomy is the most common emergency surgery.1 Intestinal malrotation is an anomaly in which the midgut is unable to complete its necessary rotation around the superior mesenteric artery and is fixated to the peritoneum in reverse orientation. In addition to preventing the cecum from assuming its normal position in the right lower quadrant, the condition also results in the superior mesenteric artery and vein being located to the right of midline.2 In patients with malrotation, the appendix is generally located in the left lower abdominal quadrant.3 Acute appendicitis may immediately come to mind for patients with malrotation and situs inversus presenting with left lower quadrant pain, and prior knowledge of these conditions greatly facilitates diagnosis.4

Discussion

Many possible causes may come to mind in the differential diagnosis of patients presenting with left lower quadrant abdominal pain, including sigmoid diverticulitis, neoplasms, colon perforation, urinary tract pathologies, gynecologic pathologies, enteritis, and ileus. Acute appendicitis is among the leading causes of abdominal pain in patients presenting to emergency services, and according to the literature, appendectomy is the most commonly performed emergency surgery.1 Acute appendicitis may not be an initial consideration in patients with left lower abdominal pain, but there are four different conditions in which the appendix is located in the left lower quadrant. In order of frequency, these are situs inversus, intestinal malrotation, mobile cecum syndrome, and an appendix long enough to cross the midline. Situs inversus and malrotation are anomalies, whereas mobile cecum and long appendix are variations in anatomic position.4 While the appendix is always located in the left lower quadrant in situs inversus patients, it may be located anywhere in the abdomen in cases of mobile cecum and malrotation. Collins5 reported the prevalence of left-side appendix as 0.04% and that of left-side appendix with situs inversus as 0.016%.

Left-side appendicitis is diagnosed by basic physical examination. As with patients showing normal acute appendicitis laterality, laboratory findings provide valuable data regarding infection. Although anteroposterior chest X-ray can facilitate the identification of patients with situs inversus, the most definitive diagnostic method is computed tomography.6 Ultrasonography is the first choice for evaluation of acute appendicitis, both in patients with normal anatomic positioning and patients with malrotation or situs inversus.

In conclusion, despite its rarity in the long differential diagnosis list, the coexistence of malrotation and acute appendicitis must be considered and full utilization of available radiologic imaging methods is imperative for patients presenting with left lower quadrant pain.