A 31 year old women presents with right lower quadrant pain and nausea. The onset of severe pain was 3 hours ago, whilst she had suffered some mild discomfort in the preceding 48 hours. Past medical history includes endometriosis and ovarian cysts. Inflammatory markers and BHCG are negative (CRP is < 1).
View 2 – Longitudinal view
Describe and interpret these scans
Image 1: Transverse view of the right iliac fossa; the area of maximal tenderness. There is a blind ending, non-compressible tubular structure with bowel wall signature typical of an inflamed appendix. It measures 8 mm in diameter (normal appendix ≤ 6mm). There is some free fluid around the tip of the appendix which contains some echogenic debris. There is an additional anterior hypoechoic crescent shape measuring 5 mm in thickness and has adjacent hyperechoic adipose tissue.
The appendix dives deeply and is unable to be traced to its origin which lies retrocaecally. These findings are typical of appendicitis, and concerning for perforation with a periappendiceal abscess.
Image 2: Similar structure and findings are seen in the longitudinal view.
Ultrasound is the investigation of choice when evaluating pelvic pain in a female, or for appendicitis in a young person. Inflammatory markers are notoriously insensitive when evaluating for appendicitis, especially in the first 6 hours.
This patient had all of the primary and secondary findings of appendicitis on ultrasound except: adjacent ileus and appendicolith (specific, but not sensitive).
The histopathology showed “ulcerated appendicitis” that caused the purulent peritonitis.