An unusual presentation of congenital intestinal malrotation in a nonagenarian

Introduction Appendicitis is a common surgical pathology with many clinical presentations. Diagnosis can be challenging if there is an alteration to the normal position of anatomical structures and their relationships. Case presentation In this case, we report an unusual presentation of congenital intestinal malrotation in a nonagenarian presenting with generalized abdominal pain and lactic acidosis found to have perforated appendicitis. The patient was admitted to the Hospitalist service for abdominal pain and misdiagnosed with bowel obstruction secondary to previous “operation”. After further review of imaging malrotation with internal hernia was suggested. The patient was taken emergently to the operating room and found to have perforated and gangrenous appendix in the midabdomen. An appendectomy was performed and patient was ultimately discharged home in good condition on postoperative day four. Discussion Malrotation of the intestines is a developmental variant that occurs when normal fetal rotation of the intestines around the superior mesenteric artery and their peritoneal fixation fails to occur. Presentation typically occurs during infancy and diagnosis in an elderly patient is exceedingly rare. Operative intervention is often required as it is commonly associated with lactic acidosis or peritonitis. Conclusions Malrotation can go undiagnosed well into elderly life and can present with unusual signs and symptoms. CT is very helpful in aiding the diagnosis but itself can be misleading.