[A Case of Surgical Resection of Anaplastic Carcinoma of the Pancreas(Pleomorphic Cell Type)with Poor Response to Neoadjuvant Chemotherapy].

A 62-year-old man was incidentally found to have a pancreatic tumor by CT. He was diagnosed with pancreatic cancer by EUS-FNAB. Gemcitabine(GEM)plus nab-paclitaxel(PTX)was started as neoadjuvant chemotherapy(NAC)for resectable pancreatic cancer. However, after the end of the second course, the tumor grew rapidly and invaded the stomach, so NAC was discontinued, and surgery was performed. The pathological diagnosis was anaplastic ductal carcinoma of the pleomorphic cell type, and the histological response was Grade 1a. Multiple liver metastases appeared during adjuvant chemotherapy with S-1, so GEM plus nab-PTX and modified FOLFIRINOX were administered, but the therapeutic response was poor, the patient died 9 months after surgery. Anaplastic carcinoma has a poor response to chemotherapy and may be included with cancers showing treatment resistance to NAC, as seen in our case. It is necessary to pay attention to anaplastic carcinoma during the course of NAC for pancreatic cancer.