Acute perforated appendicitis in pregnancy

Case contributed by Hoe Han Guan
Diagnosis certain


Acute right loin pain with vomiting and fever. Third trimester pregnancy.

Patient Data

Age: 30 years
Gender: Female

Significant fat streakiness at the right lumbar region, suggestive of active on-going infective and inflammatory process. Thickened peritoneum at the right paracolic gutter as well as thickened right Gerota's fascia. Cecum is mobile and high in position at right lumbar region. A blind ending tubular structure measures up to 1.6cm may represent dilated appendix. A focus of calcification noted at the center of fat stranding, which is likely to represent appendicolith.

No pneumoperitoneum. No intramural gas.

Minimal right perinephric collection and slight bowel wall thickening of the ascending colon, represent secondary inflammatory changes.  No hydronephrosis and hydroureter.

Gravid uterus with placenta at the anterior aspect and cephalic presentation.

No ascites. No abdominal and pelvic lymphadenopathy.

Bibasal lung atelectasis. No pleural effusion. 

Case Discussion

CT features are in keeping with acute appendicitis with appendicolith. Secondary inflammatory process onto the right kidney and ascending colon. Complicated with perforation should be considered in view of the large degree of fat standing and ill definition/poorly marginated dilated appendix.  The patient proceeded with emergency appendectomy. 

Intra-operative findings:

  • Gravid uterus at 35 weeks

  • Very deep retrocecal appendix

  • Pushed up by gravid uterus, almost reaching lower edge of liver

  • Macerated, perforated appendix at tip and body

  • Contained pus (10 cc) over the right lumbar region

  • Base of the appendix healthy 

Ultrasound abdomen is the recommended first imaging examination for abdominal pathology of pregnant lady. Ultrasound has been performed for this patient, which only showed right perinephric collection and was initially treated as acute right pyelonephritis. However, due to persistent fever and high inflammatory markers (raised white blood cell counts and C-reactive protein), proceeded with contrast enhanced CT abdomen to rule out deep seated abscess and acute appendicitis. 

The normal appendix position is usually altered due to gravid uterus, making clinical diagnosis challenging. The ideal next cross sectional imaging modality should be MRI abdomen/pelvis (without contrast gadolinium) rather than CT scan (ionizing radiation).

How to use cases

You can use Radiopaedia cases in a variety of ways to help you learn and teach.

Creating your own cases is easy.

Updating… Please wait.

 Unable to process the form. Check for errors and try again.

 Thank you for updating your details.