Appendicolith With Acute Appendicitis

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Over the past 24 hours, an 18-year-old boy had generalized abdominal pain and fever. On presentation to the emergency department, he was febrile, with a temperature of 38.3°C (101°F), and tachycardic (heart rate, 120 beats per minute); blood pressure and respiration rate were normal. He had a past history of intermittent asthma. Abdominal examination elicited tenderness over the right iliac fossa. The remaining examination findings were unremarkable.

An abdominal radiograph revealed a round calcification overlying the sacroiliac joint (arrow) suggestive of an appendicolith. A CT scan of the abdomen showed an appendicolith of 2.2 cm in diameter with a dilated appendix. During laparoscopic appendectomy, a perforated appendix with an appendicolith was found. The diagnosis of acute gangrenous appendicitis was confirmed by histopathologic examination.

Fecaliths formed by calcium salts and fecal debris layered and lodged in the appendix are called appendicoliths or appendiceal fecaliths and are a known cause of appendicitis in children. However, they have also been identified in asymptomatic persons. Appendicoliths may cause right iliac fossa pain in the absence of obvious appendiceal inflammation.¹

Although appendicoliths are significantly associated with appendicitis, the presence of an isolated appendicolith on CT appears to be insufficient for the diagnosis of acute appendicitis. In a retrospective review of 104 children who underwent CT for suspected appendicitis, an appendicolith was found in 39 (65%) of 60 children with appendicitis and in 6 (14%) of 44 children without appendicitis.² An appendicolith detected on CT had a sensitivity of 65%, a specificity of 86%, and a positive predictive value of 74% for the diagnosis of appendicitis.² In this patient, the dilated appendix was suggestive of appendicitis.

The incidence of an isolated appendicolith in children with no CT signs of appendicitis has been reported to be 2.6%.³ Subsequent appendicitis develops in only a few children with an isolated appendicolith, which suggests that these children are at low risk for appendicitis.

The presence of an appendicolith is associated with earlier and higher rates of appendiceal perforation in pediatric patients with acute appendicitis.⁴ In a study of 388 patients who underwent appendectomy, appendiceal perforation occurred at 91 hours in patients with an appendicolith (57%) versus 150 hours in those without an appendicolith (36%).⁴

For patients with acute appendicitis, the treatment is appendectomy. However, for patients who have a ruptured appendix with an inflammatory mass or abscess, one approach is nonoperative management with intravenous antibiotics. Of the patients who are treated with antibiotics, recurrence of appendicitis is higher in the presence of an appendicolith. Thus for patients with an appendicolith, interval appendectomy has been recommended to prevent recurrence.⁵

A retained, or dropped, appendicolith is a rare complication that can occur as a consequence of stone expulsion from the appendix before or during appendectomy. A retained appendicolith after appendectomy can manifest as an abscess or, less commonly, as a fistula and nonhealing wound.⁶ This patient recovered well without complications.