High-grade pancreatic intraepithelial neoplasia diagnosed based on changes in magnetic resonance cholangiopancreatography findings: A case report

Figure 1 Computed tomography revealed a 5-mm round cyst in the pancreatic tail (arrow) but with no solid mass, atrophy, or fatty change in the pancreas. A: Pancreatic parenchymal phase; B: Equilibrium phase.

Figure 2 Findings of endoscopic ultrasonography at first visit to our institute. A and B: There were diffuse high echoic spots (orange arrows) in the whole pancreas, indicating early chronic pancreatitis; C: Small round cysts (arrowheads) were found in the pancreatic tail; D: There was no caudal main pancreatic duct dilatation in the pancreatic tail (white arrow).

Figure 3 Findings of magnetic resonance cholangiopancreatography at first visit to our institute. A: The main pancreatic duct (MPD) had poor description in a 20-mm range (arrows) at the pancreatic body/tail, but there was no dilation of the caudal MPD; B: Other sequence of magnetic resonance cholangiopancreatography revealed irregular MPD in the same position (arrowheads).

Figure 4 Changes of magnetic resonance cholangiopancreatography findings. A: Magnetic resonance cholangiopancreatography (MRCP) findings demonstrated no change at 6 months; B: Other MRCP sequence at 6 months; C: Caudal cyst has grown (arrows) and caudal main pancreatic duct caliber has slightly increased (arrowhead) at 24 months; D: Other MRCP sequence at 24 months.

Figure 5 Computed tomography at 24 months revealed no solid space-occupying lesion but the pancreatic tail cyst has grown to 10 mm and the caudal main pancreatic duct was slightly dilated. A-C: Pancreatic parenchymal phase; D-F: Equilibrium phase.

Figure 6 Findings of endoscopic ultrasonography at 24 months. A: On endoscopic ultrasonography (EUS), the cyst was described like a solid mass (arrows); B: Contrast-enhanced EUS using Sonazoid showed the mass as a round cyst.

Figure 7 Findings of endoscopic retrograde pancreatography. A: Endoscopic retrograde pancreatography revealed that the main pancreatic duct (MPD) in the pancreatic tail was irregularly narrowing (arrows) in a 20-mm range and the caudal MPD was slightly dilated; B: Serial pancreatic juice aspiration cytology examination revealed atypical cells consistent with adenocarcinoma.

Figure 8 Pathological findings. A and B: Low-papillary and pseudopapillary adenocarcinoma cells were spread in the cyst wall; C: Malignant cells spread to the main pancreatic duct (arrow) and branch duct, in a 20-mm range toward the pancreatic body; D: Distribution of high-grade pancreatic intraepithelial neoplasia (orange points). MPD: Main pancreatic duct.