[Anaplastic Carcinoma with Osteoclast-Like Giant Cells of the Pancreas and Synchronous Liver Metastasis That Was Successfully Treated with Surgery and Chemotherapy-A Case Report].

A 76-year-old man presented with a pancreatic cystic lesion on magnetic resonance imaging before surgery for bladder cancer. Endoscopic ultrasound(EUS)suggested a malignant tumor such as a neuroendocrine neoplasm, but EUS-fine-needle aspiration was not performed. In addition, a single tumor 10 mm in size was found in the liver(S5), and liver metastasis was suspected. We judged that surgery would be useful for treating the neuroendocrine neoplasm and liver metastasis, so we performed distal pancreatectomy, splenectomy, and partial hepatectomy. Histopathological examination revealed anaplastic carcinoma with osteoclast-like giant cells and liver metastasis. Four courses of modified FOLFIRINOX and 3 courses of liposomal irinotecan plus 5-fluorouracil/Leucovorin were administered as chemotherapy, but it was discontinued due to adverse events. Thereafter, S-1 monotherapy was performed for 7 months, and the patient was alive without recurrence as of 1 year and 8 months postoperatively. Anaplastic carcinoma of the pancreas often recurs early after surgery; thus, long-term survival is difficult to achieve, even after R0 resection. Here, we report this case of anaplastic carcinoma with osteoclast-like giant cells of the pancreas and synchronous liver metastasis that was successfully treated with surgery and chemotherapy.