Pure mucinous (colloid) carcinoma of gall bladder: a rare entity

Abstract

In the biliary tract, ‘mucinous’ carcinomas in which extracellular mucin constitutes more than 50% of the tumour volume, are very rare. Those tumours in which the mucinous pattern comprises of at least 90% of the tumour are called ‘pure mucinous’ carcinomas and are exceedingly rare in the gallbladder. We describe the case of a 55 years old female, who presented with the complaints of jaundice and dull aching pain in right hypochondriac region. USG abdomen was suggestive of carcinoma along with cholelithiasis, following which cholecystectomy was performed. Grossly, a large grey-white tumour was identified whose cut surface was variegated. Sections showed a tumour which was entirely composed of pools of extracellular mucin, in which clusters of tumour cells were floating. Based on morphology and immunohistochemistry, a final diagnosis of ‘pure mucinous (colloid) adenocarcinoma’ of the gallbladder was given. This case is described owing to the rarity of this neoplasm. The clinical features, natural history and prognosis of mucinous carcinoma of GB are not very well known, due to their extreme rarity. These have been discussed in this case report. Histopathological examination is vital for a decisive diagnosis of such cases.