Two congenital anomalies in one: an ectopic gallbladder with phrygian cap deformity

The gallbladder is affected by a large number of congenital anomalies, which may affect its location, number, size, or form. Some of these malformations are very rare and may lead to misdiagnosis. An ectopic gallbladder can be misinterpreted as agenesis of the organ or as a cystic hepatic mass when intrahepatic. Given the frequency and the wide acceptance of the ultrasonographic examination of the biliary tract, radiologists should be aware of these malformations. In some cases, ultrasonographic diagnosis can be difficult. However, the use of Computed Tomography can elucidate such cases. We present the case of a patient whose gallbladder had two combined malformations but caused no symptoms. Namely, the patient had a transverse ectopic gallbladder combined with a "Phrygian cap" deformity. The incidence of ectopic locations of the gallbladder is 0.1-0.7%, whereas the "Phrygian cap" deformity can be found in 4% of patients. There is no other cases with combination of these two entities reported in the literature. Ultrasonographic and CT findings are presented and aspects of this malformation are discussed. The clinical significance of ectopic gallbladder is also emphasized because it may alter the clinical presentation of biliary tract diseases and pose technical problems during surgery.