Gallstone in Pediatric Population

Gallbladder calculi are more common in adult population and remain relatively uncommon in children; however, incidence of cholelithiasis in pediatric has increased, which is most common in the pre-adolescent and adolescent girls. Etiology of gallstones in pediatric population is somewhat different from that in adults. In neonates, cholestasis due to infection or genetic metabolic disorders and diuretics are the main risk factors. Among other pediatrics, hemolysis (due to sickle cell disease, thalassemia, hereditary spherocytosis), CF, IBD and obesity constitute the main etiological factors. Distribution of gallstone types in children also differs from the adults, with cholesterol stones being the most common type of stone in adult population and black pigment stones being the most common type in children. However, pediatric may also present with cholesterol, calcium carbonate, protein-dominant or brown pigment stones. Gallstones may be symptomatic in only ۲۵% of cases. The most common presentation is with biliary colic (RUQ abdominal pain which may be referred to right shoulder, especially after a fat-rich meal). A Murphy sign (expiratory arrest with palpation in RUQ) is thought to be pathognomonic. Jaundice is more frequently seen in children with cholelithiasis compared with adult cases. There are various imaging modalities for diagnosis of gallstones: Radiopaque stones (۱۵-۲۰% of the cases) are visible on plain radiography, which may sometimes have a lamellated appearance or contain foci of trapped gas. Ultrasound is considered the gold standard for detecting gallstones. They present as echogenic focus with posterior acoustic shadowing regardless of pathological type. Gravity-dependent movement is often seen with a change of patient position. They may demonstrate twinkling artifact in color Doppler ultrasound which is particularly useful for identification of small stones. Calcified gallbladder stones are hyperattenuating to bile, making them the only type to be clearly visualized on CT scan. Other gallstones are iso or hypodense to bile and may not be clearly identified in CT scan. Gallstones are signal void or low signal in T۲ sequences and MRCP; however, their signal on T۱ depends on their type, being high signal in pigmented stones and low signal in cholesterol stones. Expectant management is the recommended approach for patients with incidentally detected asymptomatic gallstones. Laparoscopic cholecystectomy remains the standard treatment for gallstones. Complications of gallstones include: cholecystitis, cholangitis, pancreatitis, obstructive jaundice, gallbladder empyema, cholecystoduodenal fistula and Mirizzi syndrome. Differential diagnosis of gallbladder stone include ingested iron tablets (on plain radiograph), gallbladder polyp and sludge, gallbladder carcinoma and pneumobilia (on MRCP).