Tumors of the papilla of Vater, should be separated from periampullary tumors. They are not always malignant, and recent data from endoscopy series, and pathology studies, supports the adenoma-carcinoma sequence at this level. Adenomas are tubular or villous and are classified according to the degree of dysplasia. The endoscopic pattern separates exophytic tumors, sessile and easily detected, from intracanalar tumors usually detected after sphincterotomy. The malignancy of an exophytic tumor is suspected when it is ulcerated or large (over 3 cm), and is easily confirmed by biopsies. The typing of intracanalar tumors is more difficult. In a 5-year period, an ampullary tumor was detected by ERCP in 52 patients: the tumor was exophytic in 33 and intracanalar in 19. Adenocarcinoma was confirmed in 26 and adenoma in 26, resulting in a 50% ratio. Among the adenomas, 18 were fully benign and 8 had a superficial cancer focus. Therapeutic procedures included: laser photodestruction in 16, snare resection in 16, sphincterotomy in 47, stenting in 8, surgical bypass in 7, cephalic duodenopancreatectomy in 16. The 16 patients treated by laser (Nd:YAG mainly) included 8 adenomas: a complete tumor destruction was obtained in 7 (follow up from 14 to 53 months). Adenomatous recurrence was observed at 2 years in one patient. In 8 other patients the tumor was an adenocarcinoma; Laser photodestruction failed to completely destroy the tumor in 1 patient (operative control), in 7 others it was adopted as a complement to sphincteromy and stenting in palliation, but was not found very effective.(ABSTRACT TRUNCATED AT 250 WORDS)