Cross-sectional imaging is frequently used in the diagnosis of pancreatic cysts, but there can be overlap in radiographic appearance. We present a case of a patient with presumed intraductal papillary mucinous neoplasm (IPMN) who was ultimately found to have a serous cystadenoma in communication with the pancreatic duct. A literature search for serous cystadenoma communicating with the pancreatic duct was performed and the data was reviewed in the context of this case report. Three reports of patients with serous cystadenoma communicating with the pancreatic duct were identified. Review of current data revealed that endoscopic ultrasound (EUS) has an important role in distinguishing between pancreatic cystic lesions preoperatively. Distinguishing between serous and mucinous cystadenomas and IPMN is essential to guide appropriate management. Although communication with the pancreatic duct is usually pathognomonic of IPMN, rarely this may be a misdiagnosis of a serous cystadenoma and EUS may be necessary for further evaluation. If EUS cannot be performed, resection is favored to avoid undertreating a premalignant lesion.