Gallbladder mucocele caused by intestinal metaplasia in lithiasic cholecystitis: A case report and literature review of a rare association

INTRODUCTION

Mucin hypersecretion promoted by intestinal metaplasia can lead to gallstone formation. The presence of large amounts of mucin induced by a change in biliary epithelium structure is called a mucocele, a usually benign condition studied among animals but rarely described in humans. This entity must be distinguished from hydrops, a condition secondary to an impacted gallstone in the cystic duct leading to an outlet obstruction and distension of the gallbladder.

PRESENTATION OF CASE

We report a case of a 51-year-old female with lithiasic cholecystitis showing areas of intestinal metaplasia associated with a mucocele. Laparoscopic cholecystectomy was performed with an uneventful postoperative course. Macroscopic findings revealed a dilated gallbladder filled with mucoid fluid. Signs of chronic and focally acute cholecystitis with areas of intestinal metaplasia were observed microscopically.

DISCUSSION

Lithiasic gallbladders can bear a gene that is found in goblet cells of intestinal metaplasia, leading to mucin hypersecretion. Metaplasia - a benign lesion often encountered on cholecystectomy specimens - can be the precursor of carcinoma. Mucin-producing gallbladder carcinoma is a very aggressive tumor that can appear as a mucocele. Consequently, preoperative computed tomography or magnetic resonance cholangiopancreatography should be performed in the presence of an unusual aspect on sonography.

CONCLUSION

Metaplastic changes in gallbladder epithelium associated with an overproduction of mucin and lithiasic cholecystitis reported in this case is a rarity. Malignancy is an alternative diagnosis of gallbladder mucocele that must be suspected whenever preoperative imaging of the gallbladder is atypical.

Histopathologic Features of 1000 Cholecystectomy Specimens

Background: One of the most common gastrointestinal surgeries is cholecystectomy. Gallstones are the major causes of cholecystectomy and induce various histopathologic changes. Gallbladder carcinoma is rare with poor prognosis. Metaplasic changes in gallbladder epithelium are considered precancerous lesions. Objectives: This study aimed at revealing the spectrum of histopathological patterns of gallbladder diseases in cholecystectomy specimens. Methods: A total of 1004 gallbladder H & E stained slides of cholecystectomy specimens over one year were studied. Histopathological evaluation was done by 6 pathologists in terms of variables. Results: In our study, the male: female ratio was 1:2.1. The age of patients varied from 17 to 96 years with a mean age of 49.1 years. The mean age of patients with gallstones was 47.52 years and was more common in women. Cholesterol, pigmented, and mixed stones were reported in 58.36%, 39.03%, and 2.6% of gallstones, respectively. The most common histological morphology was chronic calculous cholecystitis (61.18%). The incidence of metaplasia and invasive carcinoma was 19.55% and 0.2%, respectively. Conclusions: In this study, histopathological analysis of gallbladder diseases in the cholecystectomy specimens revealed that chronic calculous cholecystitis was the most common histologic finding. Gallstones were found more commonly in women and cholesterol stone was the predominant type. Pyloric metaplasia was the most frequent type of metaplasia. The rate of invasive carcinoma is compatible with those reported in the literature. Routine histopathological analysis of the cholecystectomy specimens will help to detect incidental carcinoma and precursors of malignancy.