Ando Taro, Nitta Hiroyuki, Umemura Akira, Katagiri Hirokatsu, Kanno Shoji, Takeda Daiki, Nishiya Masao, Uesugi Noriyuki, Sugai Tamotsu, Sasaki Akira
Department of Surgery, Iwate Medical University, Yahaba, Japan.
Department of Molecular Diagnostic Pathology, Iwate Medical University, Yahaba, Japan.
Case Rep Gastroenterol. 2024 Mar 27;18(1):181-188. doi: 10.1159/000536008. eCollection 2024 Jan-Dec.
Autoimmune pancreatitis (AIP) is recognized as a disease with a good prognosis that responds well to steroids, but the complication of pancreatic ductal adenocarcinoma (PDAC) in AIP is a rare condition. We report a case of PDAC encapsulated by tumor-forming type 1 AIP.
The patient, a 65-year-old female, was found to have high CA19-9 levels and a pancreatic mass with a diameter of 30 mm on abdominal ultrasonography. Contrast-enhanced computed tomography revealed a 40-mm mass in the tail of the pancreas that had a 27-mm oligemic mass inside it. From these work-up examinations, this tumor was diagnosed as PDAC, with evidence of colonic invasion. As curative resection for PDAC, a distal pancreatectomy with splenectomy and combined colon resection were performed. Histopathological examination showed invasive PDAC surrounded by IgG4-positive plasma cell infiltration. Based on these findings, a diagnosis was made of PDAC located in the pancreatic tail capsulized by type 1 AIP. The postoperative course was uneventful, and the patient was discharged on postoperative day 15. She underwent postoperative adjuvant chemotherapy with S-1 for 6 months, and no recurrence was noted for 2 years after operation.
Currently, there are two hypothetical mechanisms of PDAC induction by AIP: (1) carcinogenic stimulation due to chronic inflammation and (2) paraneoplastic syndrome caused by AIP. Further study of the relationship between AIP and pancreatic cancer is needed, and follow-up should be conducted while keeping in mind the possibility of complications.
自身免疫性胰腺炎（AIP）被认为是一种预后良好且对类固醇治疗反应良好的疾病，但AIP并发胰腺导管腺癌（PDAC）是一种罕见情况。我们报告一例由肿瘤形成型1 AIP包裹的PDAC病例。
该患者为一名65岁女性，腹部超声检查发现CA19-9水平升高且胰腺有一个直径30毫米的肿块。增强计算机断层扫描显示胰腺尾部有一个40毫米的肿块，内部有一个27毫米的少血供肿块。通过这些检查，该肿瘤被诊断为PDAC，有结肠侵犯的证据。作为PDAC的根治性切除，进行了胰体尾切除术、脾切除术和联合结肠切除术。组织病理学检查显示侵袭性PDAC被IgG4阳性浆细胞浸润包围。基于这些发现，诊断为位于胰腺尾部的PDAC被1型AIP包裹。术后病程顺利，患者于术后第15天出院。她接受了为期6个月的术后辅助化疗S-1，术后2年未发现复发。
目前，AIP诱发PDAC有两种假设机制：（1）慢性炎症引起的致癌刺激和（2）AIP引起的副肿瘤综合征。需要进一步研究AIP与胰腺癌之间的关系，并且在随访时应牢记并发症的可能性。
