Fig. 9

A space-occupying lesion of the pancreatic tail in a 52-year-old man. Axial MRI T₁WI (a), T₂WI/FS (b), T₁WI/FS (c), and enhanced (d) sequences all showed that the lesion’s signal was similar to that of the spleen, but our radiologist’s diagnosis was pancreatic neuroendocrine tumor, which was relatively common, rather than a rarely occurring ectopic spleen. Finally, the surgical pathology confirmed an ectopic spleen in the pancreas. This thinking bias is classified as zebra retreat bias