Colloid Carcinoma of Gallbladder - Incidental Finding of a Rare Entity

Majority gall bladder carcinomas are conventional adenocarcinomas of pancreatobiliary type. Mucinous carcinomas in gall bladder constitutes 2.5% of all gallbladder carcinomas. Pure mucinous (colloid carcinomas) are even rarer. Its rarity deserves this case being highlighted. Less than twenty-five cases of mucinous carcinomas of the gallbladder have been reported so far. A 46-year-old female presented with recurrent right upper quadrant pain along with nausea and vomiting for last one year. Liver function tests & kidney function tests were within range. USG Abdomen revealed an enlarged gallbladder measuring 8x5 cm with no stones. No other abnormalities were found on USG. A simple cholecystectomy was performed for chronic cholecystitis. Gross examination of specimen showed glistening, globular, soft and cystic gall bladder filled with mucoid tenacious yellowish material. There was no discernible mass lesion. Microscopic examination revealed pools of extracellular mucinous material dissecting muscular wall containing few signet ring cells. A diagnosis of colloid or pure mucinous adenocarcinoma of the gallbladder was made. Pure mucinous carcinomas as seen in exocrine glands like breast, pancreas and skin are very uncommon in gall bladder. Mucinous variant (>50% stromal mucin) are most of the time admixed with conventional type. Mucinous carcinomas most of the time are large and advanced at the time of diagnosis and are aggressive in nature than conventional type. This case is presented owing to its extreme rarity.