Appendix (PBR 2)

Question 1

This is the most common cause of acute abdomen

Answer 1

Acute appendicitis

Question 2

Clinical diagnosis of acute abdomen

Answer 2

Abdominal pain
Nausea
Anorexia
Vomiting

Question 3

Radiograph finding of acute appendicitis

Answer 3

An appendiceal calculus (appendicolith or fecalith) in approximately 14% of patients

Appendiceal abscess or periappendiceal inflammation may result in a visible soft tissue mass in the right lower quadrant

The lumen of the cecum, as outlined by gas, will be deformed; localized ileus may be evident

Question 4

US signs of acute appendicitis

Answer 4

1. Noncompressible appendix larger than 6 mm in diameter, measured outer wall to outer wall
2. Visualization of a shadowing appendicolith
3. Inflamed periappendiceal fat becomes more echogenic and fixed moving with the appendix during compression
4. Color Doppler shows increased vascularity in the wall of the appendix

With perforation, sonography demonstrates a loculated pericecal fluid collection, a discontinuous wall of the appendix, and prominent pericecal fat

Question 5

CT is the usual imaging method of choice in men, in older patients, and when periappendiceal abscess is suspected

What are the definitive CT diagnosis of acute appendicitis

Answer 5

1. An abnormally dilated (>6 mm) appendix
2. Enhancing appendix surrounded by inflammatory stranding or abscess
3. Pericecal abscess or inflammatory mass with a calcified appendicolith

*Creator’s note:
Similar to US

Question 6

In acute appendicitis:

An inflammatory mass is seen as indurated soft tissue with a CT density of what HU?

Answer 6

Greater than 20 H

A liquefied mass less than 20 H in CT density is evidence of abscess

Abscesses larger than 3 cm generally require surgical or catheter drainage
Smaller abscesses commonly resolve on antibiotic treatment alone

Question 7

This refers to distention of all or a portion of the appendix with sterile mucus

Answer 7

Mucocele

The lumen is obstructed by appendicolith, foreign body, adhesions, or tumor

Some cases are due to mucinous cystadenomas or cystadenocarcinomas of the appendix

Question 8

Appendiceal dilation greater than how many milimiters suggests possible mucocele?

Answer 8

13 mm

Continued secretion of mucus produces a large (up to 15 cm), well-defined cystic mass in the right lower quadrant

Question 9

Other findings of mucocele

Answer 9

Peripheral calcification may be present

Rupture of the mucocele may result in pseudomyxoma peritonei

Gelatinous implants spread throughout the peritoneal cavity, causing adhesions and mucinous ascites

Question 10

Most common tumor of the appendix

Answer 10

Carcinoid tumor

The appendix is the most common location for carcinoid tumor, accounting for 60% of all carcinoids

Most occur near the tip and are round, nodular tumors up to 2.5 cm size

Question 11

Adenomas occur in the appendix usually in association with what syndrome?

Answer 11

Familial multiple polyposis

Isolated adenomas are usually mucinous cystadenomas associated with mucocele of the appendix

Adenocarcinoma of the appendix is rare a

Question 12

This is usually discovered in the clinical setting of suspected appendicitis in an older adult

Imaging demonstrates a soft tissue mass within or replacing the appendix

Answer 12

Adenocarcinoma of the appendix