Septate gallbladder: Gross and histological perspectives in an uncommon occurrence

Septate gallbladders are rare variations associated with the extra-hepatic biliary system. Available reports state that variations of gallbladder are either asymptomatic or are found associated with inflammation and stones. The present report is a morphological and histological study of a septate gallbladder. The organ was found to have a transversely oriented septa at about its middle that divided the cavity into an upper and a lower segment with a tiny communication between them. Both the cavities were grossly distended and filled with moderately large stones. The gallbladder presented a fibrous constriction on its exterior corresponding to the margin of the septa. The cystic duct and artery were single and normal. Histology revealed extensive intramural fibrosis and atrophy of smooth muscles. Epithelium demonstrated extreme thinning with loss of folds and glands, with presence of cysts and sinuses beneath. None of the anomalies could be suggested by pre-operative ultrasound imaging except the calculi.