A solid pseudopapillary neoplasm overlooked for a decade: Long-term stability and development of distal pancreatic atrophy.

Solid pseudopapillary neoplasm (SPN) is a rare pancreatic tumor with low malignant potential, most commonly observed in young women. These tumors are frequently asymptomatic and are often detected incidentally during imaging performed for unrelated reasons. We present a unique case of a 27-year-old female with a pancreatic SPN that remained undiagnosed for ten years due to its isodense appearance on initial computed tomography imaging. The lesion remained stable in size and configuration over a decade and was eventually identified incidentally. Notably, progressive atrophy developed in the distal pancreas, likely secondary to ductal obstruction by the mass. This case highlights the diagnostic challenges of atypical SPNs, emphasizes the importance of careful image interpretation, and provides rare insight into the tumor's natural history in the absence of treatment.