Epigastric Pain Caused by Left Upper Quadrant Acute Appendicitis in the Setting of Undiagnosed Intestinal Malrotation.

Acute appendicitis is a common surgical emergency that may present atypically due to anatomical variations. We report a case of a previously healthy male in his forties presenting with epigastric abdominal pain, vomiting, and fever, initially managed as gastritis. Contrast-enhanced computed tomography (CT) of the abdomen revealed acute appendicitis in the left upper quadrant on a background of previously undiagnosed intestinal malrotation. The patient underwent emergency laparoscopic appendectomy, with intensive perioperative care for septic shock. He ultimately made a full recovery. This case highlights the importance of maintaining a high index of suspicion for acute appendicitis in adults presenting with epigastric pain and illustrates the role of early CT in identifying atypical presentations caused by underlying anatomical variants.