the incidence of acute appendicitis within an external hernia accounts for 0.13 - 1% of all acute appendicitis . amyand hernia is well known to surgeons ; it was named after claudius amyand who performed appendectomy for perforated appendicitis in the inguinal hernia sac in 1735 . in the case of femoral hernia , it is called de garengeot hernia , after a french surgeon who first described it in the literature in 1731 . de garengeot hernia is reported to account for 0.5 - 3.3% of all femoral hernias . because of the rarity and the lack of typical symptoms associating with acute appendicitis , achieving preoperative diagnosis is very difficult . a 90-year - old female was referred to our institution with a 3-day history of right inguinal swelling and inguinal pain which the patient recognized few hours prior to admission . the egg - sized mass , located slightly lower than the inguinal ligament , was red from inflammation and severe pain was induced by direct compression . physical findings revealed inguinal tenderness , but there were no complaints of abdominal pain in the right lower quadrant , nausea , or vomiting . laboratory findings showed a slight elevation of crp ( 0.49 mg / dl ) , the rest of the data was in the normal range . abdominal x - ray showed no gas - fluid levels and no signs of small intestinal dilatation . pelvic ct revealed a small round mass right beside the femoral artery and vein with the density of air and fluid ( fig . a small amount of ascites was present in the pelvic space . under the diagnosis of incarceration of the right femoral hernia involving the small intestine , the inguinal duct was opened by the frontal approach and the inguinal ligament was amputated , loosening the femoral ring . the hernia sac was revealed and the content of the sac was a congested and inflamed appendix ( fig . there was no evidence of perforation and abscess , so the hernioplasty was completed with synthetic mesh . most of the patients are rushed to the surgical room with the inconclusive diagnosis of an incarcerated hernia . laboratory and radiological findings are usually nonspecific . retrospectively , the intestine in our case was blind - ended and had intramural air and wall thickening , all positive findings of an appendix ( fig . ct findings of de garengeot and amyand hernia demonstrate intramural air density in an incarcerated hernia sac indicating intestinal involvement , but lack obstruction or dilatation of the small bowel . although few cases have reached the right diagnosis before surgery , ct scan is the best modality to distinguish de garengeot and amyand hernia from other incarcerated hernias as ct scan can easily reconstruct  air - weighted conditions from raw data . either the appendicitis started first and then the inflamed appendix moved into the hernia sac , or the existence of the appendix in the hernia sac is the initial incident and strangulation of the appendix occurred . in this case , the discoloration of the serosa at the base of the appendix suggests strangulation by the femoral ring . most authors conclude that appendectomy via the hernia sac is adequate , but in some cases where the perforated appendix is involved , the transabdominal approach may be more sufficient if abdominal abscess might also be present . the laparoscopic approach for de garengeot hernia as well as other incarcerated hernias is still controversial . laparoscopy might be a good technique to determine the condition of the hernia , but due to the difficulty in preoperative diagnosis , the laparoscopic procedure is unlikely to be the first choice for surgical approach . conclude that the limitation of the laparoscopic procedure is expansion of the inflammation of the appendix . as for the repair of the hernia , some authors suggest that delayed repair or suturing repair should be recommended rather than synthetic mesh in anticipation of infection . however , in recent studies , the consensus is that if there are no signs of abscess formation or perforation , repair by prosthetic mesh is possible without infection or recurrence . nguyen and komenaka pointed out that the factors contributing to the increased incidence of infection is the delay in diagnosis . in this case , the operation was performed immediately and no abscess formation was found in the hernia sac . when intramural air is present in an incarcerated hernia sac without sings of bowel obstruction , we should consider amyand or de garengeot hernia as one of the possible diagnoses .