Appendicoliths, the little giants: A narrative review

This narrative review aims to collate the data in the existing literature on appendicoliths, by reviewing the available information on appendicoliths that have been previously reported in 24 publications, and providing the information in one article.

Appendicoliths are frequent culprits in causing luminal obstruction of the appendix, leading to appendicitis. They are calcified masses formed as a result of the aggregation of faecal particulates and inorganic salts within the lumen of the appendix. The presence of appendicoliths in an inflamed appendix influences the patient's treatment, as surgery is usually done to avoid appendix perforation and abscess formation, and also to prevent a future recurrence of the disease. Appendicoliths are mostly imaged using CT, Ultrasound, and plain X-rays; however, CT is the most frequently used modality, particularly in the imaging of complications caused by 'retained' appendicoliths. 'Retained' appendicoliths and their consequential abscesses have been reported in the sub-hepatic and intrahepatic regions, pelvic and tubo-ovarian regions, gluteal region, subcutaneous layer, subphrenic region, and through the diaphragm into the chest cavity.

This review provides useful information on the imaging appearances and complications caused by the presence of appendicoliths in an inflamed appendix, and it also provides information on the clinical implications of 'dropped' appendicoliths during appendectomy.

Based on the findings of this review, it is recommended that the appropriate imaging modality (ultrasound and/or CT) should be considered when imaging appendicoliths and its complications. It is also suggested that retained appendicolith be considered a differential diagnosis when imaging patients with a history of appendectomy due to complicated appendicitis/perforation.