Fig. 13

63-year-old woman with prior localization of melanoma on the left thigh, who had been treated by ICIs for 16 months. A nodular 18F-FDG focus can be seen in the pancreatic head (B: axial PET slice) without concordant anomaly at CT (A). Given that this pattern was unusual, MRI was performed a week later and showed patterns consistent with pancreatic adenocarcinoma: ill-defined mass of the pancreatic head on T2 sequence (C), this lesion appearing hypointense on T1 sequence arterial phase after gadolinium injection (D), hyperintense on diffusion sequence and displaying hypercellularity on ADC sequence. Given that PET was otherwise normal, a biopsy was performed and confirmed pancreatitis. Subsequent PET showed spontaneous recovery (data not shown)