Synchronous Pancreatic Neoplasms Involving Pancreatic Ductal Adenocarcinoma: A Systematic Review of Case Reports

Background: Pancreatic ductal adenocarcinoma (PDAC) is the most common pancreatic malignancy and is characterized by a very unfavorable prognosis. Rarely, patients may develop synchronous PDAC and another distinct primary pancreatic tumor, such as a pancreatic neuroendocrine tumor. This systematic review consolidates published case reports describing the presentation, imaging characteristics, management, and outcomes of patients with synchronous PDAC and other pancreatic malignancies. Methods: A comprehensive search of PubMed and Scopus identified 26 relevant case reports, with inclusion criteria focused on histologically confirmed synchronous pancreatic tumors and exclusion of metastatic disease. Results: The majority of patients present with two pancreatic lesions, often located in both the body and tail of the pancreas. Diagnostic imaging modalities, such as computed tomography and endoscopic ultrasound, reveal common findings. Tumor markers, particularly CA 19-9, are often elevated and aid in the diagnosis. Surgical approaches also vary according to tumor location and staging, with procedures ranging from Whipple surgery to total pancreatectomy. Chemotherapy is frequently employed postoperatively. Notably, lymph node involvement and larger tumor size are associated with poorer prognoses. Conclusions: In conclusion, these patients may present with a common or non-common clinical picture as well as laboratory and imaging findings, constituting an important and unique diagnostic and therapeutic challenge.