[Neurinosarcoma of Vater's papilla. Apropos of a case].

Neurinosarcoma of Vater's ampulla is rarely observed. A case is presented in which the tumour did not occlude the ampulla and was thus detected intraoperatively. The head of the duodenum and the pancreas were ablated. Histological examination showed a fasciculated neoformation, in which the individual fasciculi ran parallel to or crossed each other. The nuclei displayed distinct atypical pictures. The little cytoplasm there was could only be clearly made out in areas involved in oedematous dissociation.