Rare Ductal Adenocarcinoma of the Pancreas in Patients Younger than Age 40 Years: An Analysis of Its Features and a Literature Review

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 clinico-pathologic 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 ≤ 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.