PMC3573793_01
a, b Abdominal ultrasound revealed a low echoic mass of 13 mm in diameter in the pancreatic body. Dilatation of the MPD was not observed. c, d Contrast enhanced computed tomography showed neither a pancreatic mass nor a dilated MPD. e Endoscopic ultrasound showed a low echoic mass of 20 mm in diameter in the pancreatic body. f Endoscopic retrograde pancreatography revealed a strictured segment of 2 mm in length in the MPD without obvious upstream dilatation at the pancreatic body. g Pancreatic juice cytology revealed adenocarcinoma (Papanicolaou stain).
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F1
Abdominal ultrasound revealed a low echoic mass of 13 mm in diameter in the pancreatic body without upstream dilatation of the main pancreatic duct (MPD) (fig. 1a, b). Contrast enhanced computed tomography showed neither pancreatic mass nor dilated MPD (fig. 1c, d). Endoscopic ultrasound showed a low echoic mass of 20 mm in diameter in the pancreatic body (fig. 1e). Since pancreatic cancer was suspected in the pancreatic body, she underwent endoscopic retrograde pancreatography, which showed a strictured segment of 2 mm in length in the MPD at the pancreatic body (fig. 1f). Cytological examination of the pancreatic juice obtained during endoscopic retrograde pancreatography revealed adenocarcinoma (fig. 1g).
a The resected specimens were cut at a slice thickness of 5 mm. PanIN lesions were observed in 15 slices. b Schematic drawing of the localization of PanIN lesions. PanIN-3s were observed mainly in the branch pancreatic ducts accompanied by normal epithelia in the MPDs between them. PanIN-2 and -1 were also seen around PanIN-3. Microinvasions of PanIN-3 were observed in three different branch pancreatic ducts. c A whitish mass of 15 mm in diameter was observed in the pancreatic body (arrows) and corresponded to pancreatitis shown in d. d Pancreatitis caused by occlusion of the branch pancreatic ducts (H&E). Fibrotic change of acinus was seen around the branch ducts that were almost occluded by the papillary growth of PanIN-3 (asterisks). e-g PanIN-3 (g) and PanIN-2 (f) lesions observed in the MPD and branch ducts (H&E, overview in e and detailed view of the black boxes in f and g). h, i Normal epithelia in the MPD observed between PanIN lesions in the branch ducts (H&E, slice no. 8, overview in h and detailed view of the black box in i). j Microinvasion of PanIN-3 (H&E). PanIN-3 slightly invaded beyond the basement membrane of intraductal epithelia (asterisk).
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F2
The resected specimens were fixed in formalin and cut at a slice thickness of 5 mm as shown in fig. 2a. PanIN lesions were observed in 15 slices (fig. 2b). A slice in the pancreatic body (slice no. 5) showed a whitish mass of 15 mm in diameter (fig. 2c) which was identified as pancreatitis by subsequent microscopic examination (fig. 2d). PanIN-3 according to the definition of the consensus guideline mainly in the branch ducts (fig. 2b, e, g). PanIN-3 (fig. 2b, e, f). PanIN-3s were located separately in branch ducts with normal epithelia in the MPD between them (fig. 2b, h, i), indicating that they originated from different sites of the branch ducts. PanIN-3s invaded microscopically beyond the basement membrane in three adjacent branch ducts (fig. 2j).