Fibrocalculous pancreatic diabetes misdiagnosed as type 1 diabetes for years:A case report and literature review

Objective To report a case with fibrocalculous pancreatic diabetes (FCPD) who was misdiagnosed as type 1 diabetes (T1DM),and provide evidence for the differential diagnosis. Methods The diagnosis,treatment and clinical characteristics of a 30-year-old male FCPD patient admitted to our department in 2019 were analyzed. Results The patient had been diagnosed as type 1 diabetes for 13 years.He was admitted to our hospital for abdominal pain and vomiting.Laboratory testing results indicated that blood ketone body was positive,glutamic acid decarboxylase antibody was positive,and his blood amylase and lipase increased significantly.Abdominal CT indicated acute attack of chronic pancreatitis,while pancreatic ultrasound showed uneven pancreatic echo with dense calcification.By reviewing the history,although the patient had poor islet function and positive islet antibody,the pancreatic imaging examination showed typical pancreatic calcification,which confirmed that the patient was FCPD rather than type 1 diabetes. Conclusion The key of differentiating FCPD and type 1 diabetes is not whether there are combining ketone disease and auto-antibodies positive or not,but is pancreatic imaging changes.