Appendiceal diverticulitis

Case contributed by Dr Michael P Hartung

Presentation

Left lower abdominal pain.

Patient Data

Age: 40 years
Gender: Male
CT

Presentation

Single inflamed diverticulum projecting from the leftward aspect of the appendix, which abuts the sigmoid colon. Appendiceal submucosal edema/thickening measuring up to 12 mm. Appendix contains a small amount of oral contrast and air.

Inflammation appears centered on the diverticulum, not the appendix, which can best be appreciated on the coronal reformatted images. No periappendiceal fluid collections. Mild reactive thickening of the right ureter. Multiple cecal diverticula.

CT

1 week later with diffuse abdominal pain

CT performed one week later shows anatomic separation of the sigmoid colon and appendix. Improved thickening/submucosal edema of the appendix and decreased inflammation surrounding the appendiceal diverticulum. Currently there is a small amount of residual stranding and fluid near the appendiceal tip, without organized fluid collection or free intraperitoneal air. No other acute findings.

CT

Annotated images

Annotated images of both studies. 

Case Discussion

The CT at presentation was read as "probable sigmoid diverticulitis causing reactive appendicitis", with the the caveat that the patient should be reimaged if he had persistent or worsening abdominal pain in order to ensure no appendiceal complication occurred. Primary acute appendicitis was felt unlikely due to the presence of oral contrast and air within the appendiceal lumen, and because the inflammation was centered the diverticulum. Appendiceal diverticulitis was felt unlikely because it is so rare. 

The patient returned one week later with diffuse abdominal pain. Follow-up CT images show definitively show that the inflamed diverticulum arose from the appendiceal tip, not the sigmoid colon. The inflammatory findings are now nearly resolved, with a small amount of remaining fluid/stranding. Nothing acute was found to account for his worsening pain. 

Appendiceal diverticulitis is a rare condition. The etiology and pathogenesis of acquired appendiceal diverticulosis is unknown. These patients are thought to have a higher risk of complications such as perforation and neoplasm1. Therefore, appendectomy is recommended in most cases.

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Case information

rID: 61802
Published: 21st Jul 2018
Last edited: 4th Oct 2018
Inclusion in quiz mode: Included

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