Uncommon and Unexpected Gallbladder Lesions
Gallbladders are one of the frequently encountered specimens in routine surgical pathology practice. This study was undertaken to know the frequency of uncommon lesions and the significant incidental findings in cholecystectomy specimens. Cholecystectomy specimens that were received over a period of three years were analysed. Of these 98% were removed for cholelithiasis with cholecystitis. Incidental findings in these cases included cholesterolosis, adenoma (papillary), adenomyoma, adenomyomatosis, and inflammatory polyp. There were six cases of primary carcinoma and one metastatic carcinoma. Carcinomas often present with signs and symptoms of cholecystitis and confound diagnosis. One case of carcinoma had a mucocele. Five cases of choledochal cysts and one of choledocholithiasis with a choledocho-duodenal fistula were seen. Adenomas are benign neoplasms whose malignant potential is controversial. Adenomyomas are tumour-like lesions which may be mistaken for malignancy. Choledochal cyst is a common cause of obstructive jaundice in childhood and is associated with chronic cholecystitis. Hence it is essential that all gallbladders that are removed get thoroughly sampled so as to exclude the presence of malignancy or other rare lesions.
Cholecystectomy specimens are frequently encountered in routine pathology practice. The usual indication is for symptomatic cholelithiasis. Careful sampling can reveal rare lesions as well as malignancies. Primary gallbladder carcinoma is an uncommon malignancy and sometimes not suspected clinically. This study was undertaken to know the frequency of uncommon lesions as well as rare gallbladder lesions.
Material and Methods :
The cholecystectomy specimens that had been received by the Department of Pathology over a period of three years were evaluated. The specimens received were fixed in formalin. The gallbladders were thoroughly examined for any gross lesions. The entire length of the gallbladder was sampled including the neck and the fundus. After routine processing, the tissue-bits were paraffin embedded and the sections were stained with Hematoxylin and Eosin.
The total number of cholecystectomy samples received were around 2% of the total of all biopsy specimens received in our Department. The most common indication for cholecystectomy was cholelithiasis, seen in 98% of the cases. The gallbladder showed chronic cholecystitis in 85% of the cases, acute cholecystitis in 5% of the cases and acute over chronic in 10% of the cases. The rare and unexpected lesions encountered in our study are shown in Table 1.
Cholelithiasis is the most common indication for cholecystectomy. Chronic cholecystitis is almost always associated with gallstones, although there is a poor correlation between the severity of the inflammatory response and the number of stones found. These cases may also rarely present as acute cholecystitis. Most of our specimens showed chronic inflammation with few showing acute or acute over chronic inflammation. Xanthogranulomatous cholecystitis in which there is inflammation consisting of sheets of foamy macrophages, is seen in about 1.8% of cases.[2,3] We had one case of xanthogranulomatous cholecystitis in this series. Inflammatory polyps are nonneoplastic polyps always associated with chronic cholecystitis.
Gallbladder carcinoma is a rare malignancy, usually seen in the sixth to seventh decade of life, with a strong female predominance. The prevalence varies in different parts of the world. In India, the Indian Council of Medical Research has found an incidence of 4.5/lakh population in males, and 10.1/lakh population in females in North India and 1.2/lakh population in South India respectively. Carcinoma often presents with signs and symptoms of cholecystitis and may not be suspected clinically and sometimes even in gross examination. Hence, it is essential that all gallbladders that are removed are thoroughly sampled.[7,8] Associated cholelithiasis may be seen in 80% of cases. We had one case which presented as cholecystitis, and malignancy was not suspected clinically. These tumours are located in the body or fundus in 90% of the cases. On gross appearance they may be seen as nodular or polypoid masses, as a thickening of the wall or as a diffusely infiltrating tumour (Figures 1A & 1B).
Microscopically, the tumour is usually an adenocarcinoma. In our study one case had only tumour thrombi in the blood vessels of the wall which indicated that it was a metastatic tumour (Figures 2A & 2B).
Mucocele (hydrops) may be seen in about 3% of the cases with cholelithiasis and is due to an impacted stone or tumour in the neck of the gallbladder or cystic duct. One of the gallbladders with carcinoma in this series was associated with a mucocele.
Choledochal cyst is a focal fusiform or spherical dilatation of the common bile duct. It is a common cause of obstructive jaundice in childhood and is associated with chronic cholecystitis. It can also occur rarely in adults. Our study had four cases in children and one in an adult. Choledocholithiasis is nearly always secondary to cholelithiasis. There was one case of choledocholithiasis with a choledocho-duodenal fistula.
Adenomas are incidental findings and have an incidence of 0.3-0.5%. These are benign tumours and about 50-65% are associated with stones. They are usually small and solitary, occurring in the body of the gallbladder. They can be multiple in about 10% of the cases. They may be pedunculated or sessile. Microscopy shows papillae lined by dysplastic cells. Their malignant potential is controversial. Some studies have found that 20% of adenomas progress to carcinoma.[10,11]
Adenomyoma (the localised or segmental form) and adenomyomatosis (the diffuse form) are seen as incidental lesions in 2-5% of cholecystectomies. They usually occur in middle-aged to elderly individuals. They occur in the body or in the fundus. The histogenesis is uncertain. They are thought to be either reactive hyperplastic lesions or possibly hamartomatous lesions. They are composed of glandular/cystic spaces within hyperplastic smooth muscle bundles. Ultrasonographically and on gross examination the lesions may be mistaken for carcinoma. There is no evidence of a preneoplastic nature. We found one case each of adenomyoma (Figure 3) and adenomyomatosis (Figure 4) in our series.
Cholesterolosis is a condition where the gallbladder shows lipid deposits in the form of yellow flecks against the bile-stained green background of the gallbladder. The incidence varies from 9 to 26%.
This study indicates that cholecystectomy when performed for cholecystitis may also harbor a gamut of benign lesions, some mimicking malignancy, as well as sometimes, a host of unsuspected malignancies. A high index of suspicion, a detailed gross examination and thorough histopathological examination of all gallbladder specimens is essential to avoid missing a malignant lesion.
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- Howard TJ, Bennion RS, Thompson JE. Xanthogranulomatous cholecystitis: a chronic inflammatory pseudotumour of the gallbladder. Am J Surg. 1991; 57:821.
- Gallbladder polyps: inflammatory, hyperplastic and neoplastic types. Surg Pathol. 1988; 1:203-13.
- Hamilton SR, Aaltonen LA. World Health Organisation Classification of Tumours of the Digestive System, Lyon, IARC Press; 2000; 206-14.
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- Giang TH, Ngoc TT, Hassell LA. Carcinoma involving the gallbladder; a retrospective review of 23 cases – pitfalls in diagnosis of gallbladder carcinoma. Diagn Pathol 2012; 7:10.
- Weyant MJ, Maluccio MA, Bertagnoli MM, Daly JM. Choledochal cysts in adults: a report of two cases and review of the literature. Am J Gastrenterol. 1998; 93:2580-3.
- Christensen AH, Ishak KG. Benign tumours and pseudotumours of the gallbladder. Report of 180 cases. Arch Pathol Lab Med. 1970; 90:423-32.
- Sato H, Mizushima M, Ito J, Doi K. Sessile adenoma of the gallbladder. Reappraisal of its importance as a precancerous lesion. Arch Pathol Lab Med. 1985; 109:65-9.
- Ozgonul A, Bitiren M, Guldur ME, Sogut O, Yilmaz LE. Fundal variant adenomyomatosis of the gallbladder: report of three cases and review of the literature. J Clin Med Res. 2010; 19:150-3.
- Parrilla-Paricio P, Garcia-Olmo D, Pellicer-Franco E, et al. Gallbladder cholesterolosis: an etiological factor in acute pancreatitis of uncertain origin. Br J Surg. 1990; 77:735.