Acute Appendicitis Presenting With Right Upper Quadrant Pain

Right upper quadrant and epigastric pain, accompanied by nausea and vomiting, prompted a 50-year-old woman to seek medical attention. She had a history of irritable bowel syndrome and a remote history of kidney stone disease, spinal fusion, and tubal ligation.

The patient was afebrile. Physical examination revealed right upper quadrant tenderness and a positive Murphy’s sign. No rebound tenderness was noted. White blood cell count was slightly elevated with a left shift. Comprehensive metabolic panel, amylase and lipase levels, and urinalysis were normal. Abdominal ultrasound showed a normal gallbladder, pancreas, common bile duct, abdominal aorta, and kidneys. The appendix was not visualized. A CT scan of the abdomen revealed an inflamed appendix that was ascending inferior and medial to the lower tip of the liver with the tip of appendix (black arrow) positioned posterior to the gallbladder (white arrow).

Laparoscopic appendectomy confirmed the diagnosis of acute appendicitis.

The differential diagnosis of acute appendicitis depends on factors such as the anatomic location of the inflamed appendix, the stage of the inflammatory process, and the patient’s age and sex.1 A retrocecal appendix may cause principally flank or back pain; a pelvic appendix, principally suprapubic pain; and a retroileal appendix, testicular pain, presumably from irritation of the spermatic artery and ureter.1 Physical findings are determined principally by the anatomic position of the inflamed appendix.

Anatomic variations in the position of the inflamed appendix lead to deviations in the usual physical findings. In this case, a long appendix with the inflamed tip in the right upper quadrant caused symptoms mimicking typical cholecystic pain—either because of direct irritation of the gallbladder or proximity to the hepatic capsule or both. Since the appendix was not in direct contact with the peritoneum, no peritoneal symptoms were appreciated.

This case is interesting because appendicitis was not initially on top of the differential diagnosis list as a result of the unusual clinical presentation. Ultrasound demonstration of a normal appendix, which is easily compressible and measures 5 mm or less in diameter, excludes the diagnosis of acute appendicitis.2 The study results are considered inconclusive if the appendix is not visualized and there is no pericecal fluid or mass,2 as in this case. Ultrasound has limited application in this case because of the unusual anatomic position of the appendix. It is not easy to find an inflamed appendix by ultrasound in an unusual position as it can be simply mistaken for the bowel. CT scanning, however, is an excellent technique for identifying appendicitis as well as other inflammatory processes masquerading as appendicitis.