Ciliated foregut cyst of the gallbladder: report of a case.

We report the rare case of a gallbladder cyst arising from the foregut remnants. A 36-year-old woman was referred to our hospital after screening ultrasonography (US) detected a tumor in the gallbladder. On admission, she was well and her blood analyses were all normal. US showed a cystic mass with internal high-echoic lesions, and computed tomography (CT) demonstrated a protruding tumor with slight enhancement in the gallbladder. Angiography provided no additional information; however, sequential CT-arteriography (CTA) clearly demonstrated that this tumor was a cystic lesion. Surgical exploration was performed, first because of the difficulty in establishing a definite diagnosis, and also because the patient wanted the tumor removed. The resected specimen contained a unilocular cystic tumor that looked like a submucosal tumor. Histologically, the wall of the cyst was lined by ciliated stratified columnar epithelium with interspersed goblet cells and underlying smooth muscle fibers. The mass was finally diagnosed as a congenital ciliated foregut cyst of the gallbladder. Cysts of the gallbladder are uncommon and the majority are acquired. To our knowledge, this represents only the fourth report of a ciliated foregut cyst of the gallbladder in the literature. Although rare, an awareness of this entity could allow a preoperative diagnosis to be made, whereby surgical exploration may be avoided. CT-A is a very useful diagnostic tool, especially when the nature of the tumor presents a difficult differential diagnosis.