Adenomyomatosis causing an echogenic fetal gallbladder – a new association

Case report:  A primi gravida presented for a third trimester growth scan due to a history of SLE. Biometry was normal but a linear echogenicity was identified in the region of the fetal gallbladder, the gallbladder was not separately identified. The patient delivered an appropriately grown term baby with normal Apgar scores. Postnatal ultrasound identified a normal‐sized gallbladder with echogenic foci in the wall demonstrating the classical ‘comet tail artifact’ seen with adenomyomatosis. Discussion:  The fetal gallbladder can be visualized from late in the first trimester. Previous case reports of echogenicities within the fetal gallbladder have found a high rate of resolution by the time of delivery [1,2]. The persistent echogenic foci in neonates were shown to be gallstones or sludge in almost all cases. All series failed to show any neonatal consequences of these findings [1]. Adenomyomatosis is a benign condition of the gallbladder where the lining epithelium extends as down‐growth between the muscle bundles to form gland like structures, known as Rokitansky–Aschoff sinuses. Within these foci secondary cholesterol crystal deposition occurs. Sonographically these appear as echogenic foci within the gallbladder wall with the classic description of ‘comet tail artefact’. A detailed medline search failed to reveal any reported cases of neonatal diagnosis of this condition. It has only rarely been reported in children. There have been no previous case reports of echogenic fetal gallbladder confirmed as adenomyomatosis in the neonatal period. Adenomyomatosis needs to be included in differential diagnosis of the antenatal echogenic gallbladder.