Fig. 3From: Conversion surgery for initially unresectable carcinoma of the ampulla of Vater following pathological complete response to chemotherapy: a case reporta The ulcerative tumor could not be detected by follow-up endoscopy after 19 months of chemotherapy. b A biopsy specimen showed papillotubular structures with fibrous stroma. A few small, irregularly shaped ductal structures were present without invasion that suggested high-grade adenomaBack to article page