Figure 5.

Schematic diagram of the correlation of histopathologic findings with radiologic findings in the case of Furukawa et al (1996)^[3] and our second case. Serous cystadenoma communicated with the main pancreatic duct (MPD); transabdominal ultrasonography demonstrated a lobulated hypoechoic mass (arrowheads) with small cystic components (small arrows). (A) The distal portion of the MPD (large arrow) is dilated. (B) On histopathologic examination, multiple small cysts lined with a layer of flat epithelium and pancreatic duct (D, large arrow) communicating with the cystic lesion were identified. (C) Schematic description of communication between the pancreatic cystic lesion and pancreatic duct possibly due to erosive change and secondary fistula formation of the pancreatic duct. (D) Serous cystadenoma without connection with the MPD but with external compression of the MPD mimicking intraductal papillary neoplasm on imaging findings; Magnetic resonance imaging of the pancreas revealed a multiloculated cystic lesion (arrowheads) at the body of the pancreas that appeared to be communicating with the MPD (arrow). (E) The pancreatic duct (D, arrows) was very close to, and compressed by, the cystic lesion (asterisk) but not involved with the cystic lesion. (F) Schematic description of the compressed morphology of the pancreatic duct by the pancreatic cystic lesion, resulting in radiologic misdiagnosis of a true connection with the pancreatic duct.