Nasopharyngeal gangliocytic paraganglioma - A case report with emphasis onhistogenesis

Gangliocytic paraganglioma (GP) is a rare neoplasm described almost exclusi vely in the gastrointestinal tract, especially the periampullary region. Ho wever, several examples have been reported at various sites, including the stomach, jejunum, and appendix. Herein we report a case of GP involving the nasopharynx. To our knowledge, this is the first report of GP at this site . A 44-year-old woman presented with headaches and symptoms of fullness and pressure related to mass effect. An initial endoscopic biopsy was followed by surgical excision of the nasopharyngeal mass. The triphasic tumor fulfi lled the morphologic and immunohistochemical criteria for GP. The histogene sis of GP is uncertain, and the current belief is that it arises from the e mbryonic ventral pancreas. This concept is based largely on the location of most cases, which is along the embryologic migration route of the ventral pancreas, as well as the expression of pancreatic polypeptide by the tumor. The nasopharyngeal location of our case clearly refutes the pancreatic ori gin of GP. We propose that the tumor probably arises from totipotential adu lt stem cells, which in the right microenvironment differentiate along norm ative cell lineages.