Rare ductal adenocarcinoma of the pancreas in patients younger than age 40 years

BACKGROUND: Pancreatic ductal adenocarcinomas (PDACs) are extremely rare before age 40 years. The objective of the current study was to determine whether the features of PDACs in patients age < 40 years differ from those in older patients. The authors reviewed the literature and their own files. METHODS: The cases reported in the literature were evaluated to determine their precise diagnoses and characteristic features. In a series of 439 PDACs from the authors' files, tumors in patients age < 40 years were identified, and their clinicopathologic features and certain genetic features were compared with those in a selected group of patients age > 40 years. RESULTS: Of 71 pancreatic carcinomas reported in patients age < 40 years, only 20 fully qualified as PDACs. The remaining tumors represented malignancies other than PDACs, such as pancreatoblastoma, solid-pseudopapillary neoplasms, acinar cell carcinomas, and endocrine tumors. PDACs in patients age < 20 years were the absolute exception and commonly were associated with risk factors such as Peutz-Jeghers syndrome, hereditary pancreatic cancer syndrome, and preceding radiotherapy. In the authors' series of patients, there were 6 PDACs and 4 PDAC variants in patients age < 40 years (0.2%), all in male patients. These tumors compared well with the PDACs in patients age > 40 years in their pathologic and molecular findings. Three patients were age < or = 20 years, and 2 of those patients had a mucinous component with MUC2 positivity. CONCLUSIONS: The incidence of PDACs in patients age < 40 years was approximately 0.3%, and the incidence in patients age < 20 years was 0.1%. Their clinicopathologic findings were comparable to those in patients age > 40 years, but they seemed to include more variants, particularly mucinous carcinomas. In addition, PDACs in younger patients frequently appeared to be associated with genetic factors.