Acute appendicitis: subcaecal appendix

Case contribution: Dr Radhiana Hassan


  • A 51 years old man
  • No known medical illness
  • Active smoker
  • Presented with sudden onset of right iliac fossa pain
  • Associated with fever and vomiting
  • No bowel habit change
  • Similar symptoms twice few months before, spontaneously resolved with self medication
  • Clinically stable, abdomen soft, localized guarding at right iliac fossa, no ascites
  • Blood investigation Hb:12.8, TWBC:11.7
Abdominal radiograph shows no significant finding

Ultrasound findings:

  • There is a focal thickening of bowel wall at right iliac fossa region, may represent the terminal ileum
  • No obvious dilatation of the bowel seen.
  • The appendix is not visualized. However, no evidence of collection seen within the appendicular region.
  • No obvious abnormality of the caecum identified.
CT scan abdomen pelvis post contrast axial plane soft tissue window
CT scan in coronal reformatted image soft tissue window

CT scan findings:

  • The appendix appears heterogenous and dilated measuring about 1.3 cm.
  • The appendix wall is thickened associated with periappendiceal fat stranding.
  • No hyperdense structure intraluminal to suggest appendicolith.
  • Bowel loops are not dilated.
  • No ascites.

Progress of patient:

  • Laparoscopic converted to laparotomy done on the same day after CT scan
  • Intra-operative findings: pus at right paracolic gutter, clumping of bowel covering appendix, no perforation, base ishealthy
  • Appendicectomy done.
  • HPE confirmed appendicitis.

Diagnosis: Acute appendicitis

  • Acute appendicitis is a very common condition and is a major cause of abdominal surgery in young patients.
  • CT is the most sensitive modality to detect appendicitis but its use should be limited because of the radiation dose required especially in young patients
  • Ultrasound should be employed as first-line where possible.
  • Ultrasound is performed with graded compression using the linear probe over the site of maximal tenderness, with gradually increasing pressure to displace normal overlying bowel gas.
  • Ultrasound findings include distended appendix, surrounding (echogenic) inflamed fat, thickening (edema) and then later, thinning (pre-rupture) of the appendix wall. Collections (hypoechoic areas) around the appendix can also be seen.
  • CT is highly sensitive (94-98%) and specific (up to 97%) for the diagnosis of acute appendicitis. CT scan findings are almost similar what is seen on ultrasound.


  • Dr Siti Kamariah Che Mohamed.
Author: radhianahassan