Diagnostic algorithm for the imaging evaluation of a solid pancreatic mass: is it malignant?

Pancreatic masses comprise a broad spectrum of benign, inflammatory, premalignant, and malignant entities with markedly different prognoses and therapeutic implications. Pancreatic ductal adenocarcinoma (PDAC) remains the most lethal solid pancreatic neoplasm, whereas inflammatory conditions such as autoimmune pancreatitis and mass-forming chronic pancreatitis may simulate malignancy on imaging, frequently leading to unnecessary surgical resections. Given the increasing detection of pancreatic lesions through widespread use of high-resolution cross-sectional imaging, radiologists play a central role in lesion characterization, risk stratification, and guidance of further diagnostic steps. This review approaches pancreatic mass evaluation not as a catalogue of entities but as a structured diagnostic problem. A six-step algorithm organized around the central clinical question: is it malignant? is presented as the organizing framework of the manuscript, with each subsequent section addressing a specific diagnostic branch of that algorithm. The algorithm assigns a formal confidence level (high, moderate or indeterminate) at each decision node, defined by explicit imaging and clinical criteria with published accuracy data cited where available.