Situs Inversus, a Choledochal Cyst and a Horseshoe Kidney: A Strange Coincidence of Congenital Conditions

Situs inversus is a condition in which abdominal and thoracic organs are laterally transposed. The organs which are supposed to be on the right side of the abdomen are on the left and vice versa. It is a rare congenital condition; however, the exact incidence is difficult to determine as most of the cases go unnoticed until they undergo an imaging study.  We report a case of a 30-year-old female presenting with situs inversus in association with a choledochal cyst and a horseshoe kidney. She underwent imaging evaluation for non-specific abdominal pain. Her routine clinical examination revealed a soft abdomen without any tenderness. Routine laboratory tests were within normal limits. Since there was abdominal pain, ultrasonography of the whole abdomen was advised. It revealed the presence of abdominal organs on the opposite side as normally seen. The common bile duct was dilated, and lower poles of the kidneys were fused. The cardiac apex was found to be on the right. It was followed up with a computed tomography scan which confirmed situs inversus. The common bile duct was dilated without any obstructive pathology in the pancreatic head or periampullary region. Lower poles of the kidneys were found to be fused together in front of the retroperitoneal vessels through an isthmus. Based on these findings, a diagnosis of situs inversus in a case of a choledochal cyst and a horseshoe kidney was made. Situs inversus is a rare entity. Its association with choledochal cysts and horseshoe kidneys has never been reported in the literature to the best of our knowledge.