The incidence of microgallbladder varies considerably in the literature, however most studies cite an incidence of 25-35% in patients with cystic fibrosis . In patients without cystic fibrosis, it is a very rare entity, but may have an association with idiopathic neonatal hepatitis and biliary atresia .
The pathogenesis of microgallbladder in patients with cystic fibrosis is not well understood. The most popular hypothesis considers microgallbladder to be a result of chronic inflammation secondary to gallstone disease leading to gross atrophy of the gallbladder.
Microgallbladder can be evaluated on ultrasound or cross-sectional imaging, although may be difficult to visualize routinely on ultrasound . On these modalities, microgalbladder is defined by :
- length: <2-3 cm
- width: <0.5-1.5 cm
Treatment and prognosis
Generally, no treatment is necessary .