Appendicolith with Appendicitis

General considerations

• Also known as a fecolith, fecalith, coprolith
• Calcified deposit within the appendix
• Present in approximately 30% of children with acute appendicitis
• May be an incidental finding on an abdominal radiograph done for other purposes
• But, when associated with abdominal pain, there is a 90% probability of acute appendicitis
  • Also 50% higher risk of appendiceal perforation
• Of some controversy, the finding of an appendicolith may be sufficient evidence to perform a prophylactic appendectomy in asymptomatic patients given the higher rate of perforation at the time of acute appendicitis
• One of several causes of obstruction of the appendiceal lumen leading to acute appendicitis which also include
  • Lymphoid hyperplasia
  • Foreign bodies
  • Stricture
  • Tumor
  • Crohn’s disease
• For more on clinical and imaging findings of acute appendicitis, click here

• The role of imaging is to confirm clinically suspected appendicitis, rule out another diagnosis or a complication of the disease

• Conventional radiography (abnormalities seen in <50%)
• Plain-film findings become more distinctive after perforation, while clinical findings subside
• Calcified, frequently laminated, appendicolith in RLQ (in 7-15%)
• It may lie higher in a retrocecal appendix
• Appendicolith in acute appendicitis means a high probability for perforation (50%), especially in children
• Appendicolith is usually 1 cm in size of larger
• Frequently laminated
• Other signs
• Localized dilatation of cecum from focal paralysis (cecal ileus)
• Small bowel obstruction pattern
• Soft-tissue mass and paucity or absence of intestinal gas in RLQ (more often with perforation and abscess)
• Extraluminal gas bubbles (usually only with perforation and abscess)
• Large pneumoperitoneum is rare because etiology of appendicitis involves obstruction of a very small lumen containing little air
• Focal increase in thickness of lateral abdominal wall
• Loss of properitoneal fat line on right side
• CT
• The imaging study of choice  (>95% accurate) is CT, or US
• Signs of acute appendicitis include
• Distended lumen
• Circumferentially thickened and enhancing wall
• Appendicolith – homogeneous or laminated calcification in up to 25% of cases
• Peri-appendicular inflammation-linear streaky densities in peri-appendicular fat
• Peri-cecal soft-tissue mass
• Abscess
• Poorly encapsulated
• Single or multiple fluid collection(s) with air
• Extraluminal contrast material
• Focal cecal wall thickening
• "Arrowhead" sign = funnel of contrast medium in cecum centering about occluded orifice of appendix

• Perforation (13-30%)

• Appendectomy

Appendicolith with Appendicitis. Upper: Frontal close-up of right lower quadrant show a laminated stone in the region of the appendix consistent with a calcification that has formed in a viscous (white arrow). Lower: Coronal reconstruction with close-up of right lower quadrant shows a dilated appendix
with a thickened wall and surrounding infiltration of the fate (yellow arrow) containing an appendicolith (red arrow).
For these same photos, click here and here
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