“…Among them are absence of intraoperative transfusion, 2,5 absence of microscopic lymph node involvement, 1,2,5,13,19 well-differentiated tumors, 2,5,10,13 small tumor size, 14 absence of tumor at resection margins, 1,3,5 absence of perineural invasion, 4 confinement of tumor to the ampulla vs invasion into the pancreas, 4 and use of adjuvant chemotherapy. 4 In our series, the absence of perineural invasion predicted significantly improved postoperative survival.…”