Histopathological and prognostic variability of ampullary tumors: A comprehensive study on tumor location, histological subtypes, and survival outcomes

Abstract

Ampullary tumors present diagnostic challenges due to the complex anatomical and histological structure of the ampullary region. They can be classified into four types based on location: Periampullary-duodenal, intra-ampullary, ampullary-ductal, and ampullary-NOS (not otherwise specified). Periampullary-duodenal tumors are exophytic, ulcerovegetative, and often intestinal-type adenocarcinomas with frequent lymph node metastasis. Intra-ampullary tumors are polypoid and confined to the ampullary canal. Ampullary-ductal tumors exhibit sclerotic thickening in the bile or pancreatic duct and are typically pancreatobiliary-type adenocarcinomas. Ampullary-NOS includes tumors that do not fit other classifications. This study aimed to classify ampullary tumors by their anatomical localization, compare histopathological features, and assess the prognostic outcomes for each group. A total of 111 ampullary tumors were selected from 229 pancreaticoduodenectomy specimens over 10 years at our hospital. Clinical, imaging, and macroscopic findings were re-evaluated microscopically. Tumors were classified into four anatomical groups, and their histopathological characteristics and prognosis were analyzed. The cohort had a mean age of 62 ± 10.49 years, with 69 (62.2 %) males and 42 (37.8 %) females. The median survival was 28.23 months. Tumor distribution was as follows: 14.4 % intra-ampullary, 25.2 % ampullary-ductal, 10.8 % periampullary-duodenal, and 49.5 % not otherwise specified (NOS). Pancreatobiliary-type adenocarcinoma (p = 0.003), perineural invasion (p < 0.0001), and lymphovascular invasion (p = 0.002) were significantly more frequent in the ampullary-ductal and NOS groups, which were associated with poorer overall survival (p = 0.011). In addition, lymphovascular invasion and surgical margin positivity were identified as independent prognostic markers. Classifying ampullary tumors based on anatomical location is crucial due to significant histopathological and prognostic differences between the groups.