Left-Sided Perforated Appendicitis in an Elderly Man with Intestinal Malrotation: A Case Report.

BACKGROUND Left-sided acute appendicitis is rare and usually reflects congenital anomalies that misplace the cecum and appendix. Although type I intestinal malrotation (non-rotation) seldom remains undiagnosed into late adulthood, it can complicate diagnosis in older patients, whose comorbidities suggest more common causes of left lower-quadrant pain. CASE REPORT A 67-year-old man with hypertension, mixed dyslipidemia, hyperuricemia, and chronic kidney disease had 48 hours of migrating colicky abdominal pain, localizing to the left flank and iliac fossa, with fever and leukocytosis. Contrast-enhanced computed tomography showed a 12-mm inflamed, obstructed appendix in the left abdomen, absence of the retroperitoneal segment of the duodenum, and inversion of the superior mesenteric vessels - findings consistent with type I malrotation. Emergency laparoscopy confirmed a pre-ileal perforated appendix with a localized abscess; laparoscopic appendectomy and drainage were performed with mirrored ports. Histopathology demonstrated transmural necrosis and serositis. Recovery was uneventful; the patient tolerated oral diet on postoperative day 1 and was discharged on day 2 with oral antibiotics. CONCLUSIONS Type I intestinal malrotation may first present as left-sided perforated appendicitis in advanced age. Vigilant review of cross-sectional imaging for malrotation indicators, coupled with early laparoscopic intervention, is essential to prevent diagnostic delay and reduce morbidity in elderly patients with atypical abdominal pain. The rarity of such presentations in the elderly underscores the novelty of this case and the need for heightened clinical suspicion.