Tumors of the ampulla of vater: histopathologic classification and predictors of survival.

Background: The histology and clinical behavior of ampullary tumors vary substantially. We speculated that this might reflect the presence of two kinds of ampullary adenocarcinoma: pancreaticobiliary and intestinal.

Study Design: We analyzed patient demographics, presentation, survival (mean followup 44 months), and tumor histology for 157 consecutive ampullary tumors resected from 1989 to 2006. Histologic features were reviewed by a pathologist blinded to clinical outcomes. Survival was compared using Kaplan-Meier/Cox proportional hazards analysis.

Results: There were 33 benign (32 adenomas and 1 paraganglioma) and 124 malignant (118 adenocarcinomas and 6 neuroendocrine) tumors. One hundred fifteen (73%) patients underwent a Whipple procedure, 32 (20%) a local resection, and 10 (7%) a palliative operation. For adenocarcinomas, survival in univariate models was affected by jaundice, histologic grade, lymphovascular, or perineural invasion, T stage, nodal metastasis, and pancreaticobiliary subtype (p < 0.05). Size of tumor did not predict survival, nor did cribriform/papillary features, dirty necrosis, apical mucin, or nuclear atypia. In multivariate models, lymphovascular invasion, perineural invasion, stage, and pancreaticobiliary subtype predicted survival (p < 0.05). Patients with pancreaticobiliary ampullary adenocarcinomas presented with jaundice more often than those with the intestinal kind (p = 0.01) and had worse survival.

Conclusions: In addition to other factors, tumor type (intestinal versus pancreaticobiliary) had a major effect on survival in patients with ampullary adenocarcinoma. The current concept of ampullary adenocarcinoma as a unique entity, distinct from duodenal and pancreatic adenocarcinoma, might be wrong. Intestinal ampullary adenocarcinomas behaved like their duodenal counterparts, but pancreaticobiliary ones were more aggressive and behaved like pancreatic adenocarcinomas.