Optimal Surgery for Early Ampullary Carcinoma Based on a Pathological Examination Following Resection

Abstract

Introduction: The aim of this study was to investigate whether partial resection (PR) instead of pancreaticoduedenectomy (PD) is acceptable for early (Tis-T1) ampullary carcinoma (AC). Methods: Of 101 patients who underwent resection for AC between January 1985 and December 2018, 40 patients with early AC (Tis: 2; T1a: 18; T1b: 20) and 16 patients treated with PR were assesed. In addition, the lymphatic vessel distribution in the ampulla of Vater was investigated immunohistologically using D2-40. Results: The 5-year survival rate was 100% and 87.4% in the Tis-T1a and T1b patients, respectively. On pathological examination, 10.0% (Tis-T1a: 0%; T1b: 20.0%) were lymph node (LN) metastasis (+), 20.0% (Tis-T1a: 0%; T1b: 40.0%) were lymphovascular invasion (+), 5.0% (Tis-T1a: 0%; T1b: 10.0%) were microvascular invasion (+), and 0% were perineural invasion (+). For the tumor differentiation, papillary or well differentiated tumors were found in all Tis-T1a patients, but moderate in 35.0% of the T1b patients. On immunohistological examination, abundant capillary lymphatic vessels were present in the mucosa of the ampulla of Vater. In the 16 patients treated with PR, the final pathological diagnosis was T1a in 12, pT1b in 1, and pT2 in 3, and the 4 non-T1a patients all died of recurrence. Conclusions: For T1b AC, PD may be the standard treatment because of the frequencies of LN metastasis and lymphovascular invasion. Abundant lymphatic capillaries in the mucosa of the ampulla of Vater and difficulty with preoprative diagnosis of the invasion depth indicate that PR may not be acceptable for Tis-T1a AC.