Table 1 Diagnostic criteria of CA (Complicated Appendicitis) and UA (Uncomplicated Appendicitis)
From: Development of a nomogram for the prediction of complicated appendicitis during pregnancy
| Â | Macroscopic appearances | Microscopic appearances |
|---|---|---|
Normal appendix | ||
 Normal underlying pathology | No visible changes | Absence of any abnormality |
 Acute intraluminal inflammation | No visible changes | Luminal neutrophils only with no mucosal abnormality |
 Acute mucosal/submucosal inflammation | No visible changes | Mucosal or submucosal neutrophils and/or ulceration |
Simple, non-perforated appendicitis | ||
 Suppurative/phlegmonous | Congestion, colour changes, increased diameter, exudate, pus | Transmural inflammation, ulceration, or thrombosis, with or without extramural pus |
Complex appendicitis | ||
 Gangrenous | Friable appendix with purple, green, or black colour changes | Transmural inflammation with necrosis |
 Perforated | Visible perforation | Perforation; not always visible in microscope |
 Abscess (pelvic/abdominal) | Mass found during examination or abscess seen on preoperative imaging; or abscess found at surgery | Transmural inflammation with pus with or without perforation |