Background: Most pancreatic carcinomas are unresectable at the time of diagnosis, but recently the diagnosis of carcinoma in situ of the pancreas has become possible. This diagnosis can be made by the detection of cancer cells in pancreatic juice and the radiographically demonstrated lack of a mass lesion. It has greatly improved the effectiveness of surgery. Carcinoma in situ remains within the pancreatic ductal epithelium and has not yet invaded the parenchyma. However, it has often been difficult to locate carcinoma in situ by conventional diagnostic methods, such as ultrasonography, endoscopic ultrasonography, computed tomography, and endoscopic retrograde pancreatography.
Methods: Peroral pancreatoscopy and a new method of cytodiagnosis, pancreatoscopic cytology, were used to analyze 11 patients with carcinoma in situ of the pancreas, 10 with disease in the main duct of the pancreas and 1 with disease in the branch ducts. The results of pancreatoscopic cytology were compared with those of conventional pancreatic juice cytology.
Results: Under peroral pancreatoscopy, carcinoma in situ of the pancreas in the main duct appeared as papillary mucosa, irregular mucosa, or nodular mucosa. Using pancreatoscopic cytology, cancer cells were obtained from all the lesions, allowing a more thorough analysis than pancreatic juice cytology.
Conclusions: Peroral pancreatoscopy and pancreatoscopic cytology are useful for locating and diagnosing carcinoma in situ of the pancreas.