Gallbladder and extrahepatic biliary tract
A benign or malignant paraganglioma arising from sympathetic or parasympathetic paraganglia outside the adrenal gland.
Paraganglioma of the gallbladder and extrahepatic bile ducts
This generally benign neural tumour is composed of nests of neural cells (chief cells) often lined by Schwann cell-related sustentacular cells. The former are immunohistochemically positive for chromogranin A and synaptophysin and negative for keratins and S100 protein, whereas the latter are positive for S100 protein and often for glial fibrillary acidic protein (GFAP). The tumour is usually located in the outer wall of the gallbladder, but can also involve the extrahepatic bile ducts. It is usually an incidental microscopic finding in cholecystectomy specimens. Some cases occur in association with multiple endocrine neoplasia (MEN) syndromes
Mehra S, Chung-Park M (2005)
. It can be difficult to distinguish between normal paraganglionic structures and a very small paraganglioma
Gallbladder paraganglioma: a case report with review of the literature.
Arch Pathol Lab Med 129: 523-6
Bosman FT, Carneiro F, Hruban RH, Theise ND (Eds.)
WHO Classification of Tumours of the Digestive System.
International Agency for Research on Cancer: Lyon 2010