Abstract
Background : Gangliocytic paraganglioma (GP), a rare tumor occurring almost exclusively adjacent to the ampulla of “papilla of Vater”, is composed of three components, although the amounts of each of these components are highly variable. Since these tumors are usually recognized as submucosal tumors, they are seldom diagnosed by endoscopic biopsy. Although EUS-FNA is a promising sampling method for the diagnosis, the cytological features have not yet been fully elucidated.
Case : A man in his sixties visited us complaining of tarry stools. Gastrointestinal endoscopy revealed a duodenal pedunculated tumor adjacent to the ampulla of “papilla of Vater”. However, repeated endoscopic biopsies failed to show the tumor components clearly. EUS-FNA cytology revealed tumor cells composed of three types of cells, including epithelioid cells with fine granular chromatin reminiscent of neuroendocrine cells, ganglion-like large cells with prominent nucleoli, and spindle-shaped cells. These findings suggested the possibility of GP. Pancreatico-duodenectomy was performed. Histologically, the tumor located within the submucosal region was composed of the three aforementioned types of cells : epithelioid cells, ganglion-like cells, and spindle-shaped cells.
Conclusion : We encountered a case of GP and reviewed the cytological findings. This tumor is characterized by its characteristic localization, macroscopic findings and cytological findings. If the three cellular components can be properly identified by EUS-FNA, GP can be diagnosed cytologically.
