Isolated polycystic disease of the pancreas is a rare condition with few reported cases in the literature. It refers to multiple dysontogenetic, or congenital, cysts spanning the pancreas excluding those with inherited autosomal cystic diseases of abdominal organs, cystic fibrosis, and Von Hippen-Lindau disease with or without the involvement of cysts in other organs. These cystic lesions prove difficult to distinguish from those of neoplastic nature, including but not limited to intraductal papillary mucinous neoplasms, mucinous cystic neoplasms, and serous cystic neoplasms, potentially leading to unnecessary treatment. We report an incidental finding of the polycystic pancreas in a 73-year-old male upon CT for diverticulitis without any pancreas-related symptoms. A comprehensive collection of all reported cases of the isolated polycystic pancreas in the literature to date revealed that we report the oldest known patient to be diagnosed, as all other patients are between ages 13–62 with 64% being female. A thorough evaluation of the literature was completed and a diagnostic algorithm to diagnose IPDP was created to assist in the appropriate evaluation of these benign lesions to reduce the morbidity associated with unnecessary surgeries prompted by diagnostic uncertainty and the possibility of pre-malignant lesions.