A Case Report of New-Onset Diabetes Mellitus as an Early Warning Sign of Pancreatic Ductal Adenocarcinoma in an Elderly Patient: The Earlier the Diagnosis and Surgery, the Better the Prognosis

Studies have been recently conducted to find pancreatic ductal adenocarcinoma (PDAC) in high-risk groups by identifying individuals with pancreatic cystic lesions and elderly people (> 50 years) with new-onset diabetes mellitus (NODM). We report the case of a 91-year-old woman in good health with pancreatic cysts, who firstly displayed a NODM and, one month later, a PDAC. A dehydration syndrome with polydipsia and asthenia led to her hospitalization. High levels of blood glucose and glycated hemoglobin were found. An abdomen US showed a minute pancreas with some cysts. Rehydration and insulin therapy led to a good glycemic compensation. One month after discharge, she displayed weight loss, diarrhea, and jaundice. On the second admission, high levels of total and direct bilirubin, indices of hepatic cholestasis, and Ca 19.9 were found. An abdomen contrast medium CT evidenced a nodule at the pancreatic head, suggesting a malignant lesion, and dilatation of both the Wirsung duct and the whole biliary tract. Despite the lack of a histological diagnosis, the absence of signs of local invasion, metastasis, and co-morbidities as well as the rapid clinical deterioration led us to propose surgical treatment. A few days later, a pancreatoduodenectomy was performed. The histologic examination showed a moderately differentiated (G2) PDAC. The TNM staging was IIA (pT3, N0, M0) (R0). Three weeks after, she was discharged with normal liver function tests, Ca 19.9 levels, and a good glycemic compensation with insulin therapy. Five years after surgical treatment, she is still doing well displaying a normal abdomen CT follow-up, normal blood tests, including Ca 19.9, and a good glycemic compensation. Our case report denotes an exceptional duration of survival of PDAC and highlights the importance to seek its presence in every case of NODM in patients > 50 years, especially if they carry pancreatic cysts.