Histopathological study of gallbladder carcinoma and its mimics with role of carcinoembryonic antigen immunomarker in resolving diagnostic difficulties.

Background: Gallbladder carcinoma (GBC) sometimes presents with nonspecific signs, without forming a mass, mimicking benign gallbladder (GB) diseases. On the contrary, benign GB diseases may mimic GBC.

Material And Methods: We retrospectively reviewed 107 cases over a period of 3 years (May 2012-April 2015), which included 41 review cases and 66 departmental cases. Carcinoembryonic antigen (CEA) immunomarker expression was done.

Results: In 27 of the 41 review cases, the diagnoses were benign diseases of GB associated with mild-to-moderate dysplasia of mucosal glands; however, after review in our department, it was found that of these 27 cases, nine cases were actually well-differentiated adenocarcinoma of GB with diffuse CEA expression and were mis diagnosed as benign diseases of GB with dysplasia. In 32 out of 66 departmental cases, initial histopathological diagnoses were benign diseases of GB associated with dysplastic mucosal glands. After CEA staining, 11 out of these 32 cases turned out to be adenocarcinoma of the GB. Among the rest 34 (34/66) departmental primary GBC cases, no CEA expression was seen in six cases, focal expression was seen in 12 cases, and diffuse expression was seen in 16 cases. No diffuse CEA expression was seen in benign diseases of the GB with dysplasia.

Conclusion: GBC sometimes may not be diagnosed radiologically and grossly as it often presents without any mass and specific signs, which lead to under diagnosis. Some benign cases may mimic GBC and may complicate histological diagnosis. CEA expression may aid as an additional diagnostic aid in resolving diagnostic dilemmas.