Pancreatic cysts are common and are being discovered at an increasing rate on cross-sectional imaging, but only a minority progresses to cancer. Intraductal papillary mucinous neoplasm (IPMN) is the most common pancreatic cystic neoplasms and potential macroscopic precursors of pancreatic ductal adenocarcinoma. New-onset diabetes or worsening glycemic control could increase the risk of advanced neoplasia and could be an initial manifestation of IPMN with high-grade dysplasia. Herein, we present an interesting case of worsening glycemic control in long-standing type 2 diabetes (T2D) as the first manifestation of IPMN with high-grade dysplasia.

Clinical course and treatment outcome was described in this case.

A 74-year-old Thai man with well-controlled T2D for 25 years presented with worsening glycated hemoglobin from 6.9% to 8.5% for 3 months without other symptoms. Abdominal ultrasonography revealed a 1.0-cm cystic lesion at the body of pancreas with diffuse dilatation of pancreatic duct. IPMN with high-risk stigmata (solid component with internal enhancing septation) was confirmed from MRCP and EUS. A high amylase and lipase level in the cystic fluid in presumed side branch cysts suggested continuity with the pancreatic main duct. Finally, distal pancreatectomy with splenectomy was performed after a shared decision making with the patient. Histology revealed high-grade dysplasia of gastric-type IPMN spreading in the main and branch pancreatic ducts, confirming a diagnosis of mixed-type IPMN with high-grade dysplasia. The patient recovered well with unremarkable follow-up imaging and was followed up routinely. At 1 year later, the patient is doing well with twice daily insulin treatments.

Patients who have IPMNs might present with associated conditions, including pancreatitis, exocrine insufficiency, and new-onset diabetes or worsening glycemic control. A meticulous and careful approach to diagnosis, oncologic risk assessment, operative planning, and surveillance is needed to adequately address these lesions. Clinicians have to decide between conservative and surgical management by recognizing which radiological features indicate a high probability for malignant potential.