すい疾患：診断と治療の進歩 ＩＩＩ．すい臓癌 １．すい癌の診断

Efficacy of repeated cytology of pancreatic juice obtained by endoscopic nasopancreatic drainage tube for early diagnosis of pancreatic cancer: a case series including a case of carcinoma in situ

Repeated cytology of pancreatic juice obtained by endoscopic nasopancreatic drainage (ENPD) tube has been highlighted as an early diagnostic method for small pancreatic cancer, including carcinoma in situ. We report two cases of early-stage pancreatic cancer diagnosed using repeated cytology; both cases underwent curative resection. No significant masses were found on conventional imaging in either case, with only pancreatic duct strictures being observed. ENPD tubes were placed to collect pancreatic juice in both cases. In case 1, two of five pancreatic juice samples showed adenocarcinoma. Therefore, distal pancreatectomy was performed, and a PanIN3 grade neoplasm (carcinoma in situ) was identified at the branch duct near the distal stricture. In case 2, two of seven pancreatic juice samples (collected during the second tube placement) showed adenocarcinoma. Therefore, distal pancreatectomy was performed, and a PanIN3 neoplasm was identified primarily in the pancreatic duct at a narrow section with fibrosis. Partial microinvasion (<1 mm) was observed at the branch duct. Repeated cytology of pancreatic juice obtained by ENPD tube is effective for early diagnosis of pancreatic cancer, especially in cases without mass formation. However, some issues, including the appropriate number of samples, should be addressed in large prospective studies.

Value of cytodiagnosis using endoscopic nasopancreatic drainage for early diagnosis of pancreatic cancer: establishing a new method for the early detection of pancreatic carcinoma in situ

OBJECTIVES

We examined the results of pancreatic juice cytodiagnosis using the method of endoscopic nasopancreatic drainage (ENPD) to identify pancreatic carcinoma in situ and compared the images and pathologic diagnosis of pancreatic carcinoma in situ as well as clinicopathologic characteristics.

METHODS

In patients who underwent endoscopic retrograde cholangiopancreatography and had ENPD place, only patients presenting with focal stenosis and distal dilatation of the main pancreatic duct were included in the ENPD placement group. Endoscopic nasopancreatic drainage was conducted 27 times in 20 patients in the ENPD placement group. In an average session, cytodiagnosis of the pancreatic juice was conducted 5.3 times (range, 2-11 times).

RESULTS

Results of cytodiagnosis were positive in 15 of 20 patients. Results of ENPD cytodiagnosis and diagnosis of pancreatic cancer showed sensitivity of 100%, specificity of 83.3%, and accuracy of 95%. Seven of 15 patients were diagnosed with carcinoma in situ. In these 7 patients, tumor markers (carcinoembryonic antigen, CA-19-9) were within reference limits, and the tumors were not visible on imaging tests. Pathologic histology revealed a propensity for the cancer to proliferate around the stenosis of the pancreatic duct.

CONCLUSIONS

Cytodiagnosis of pancreatic juice using ENPD multiple times proved to be useful in the diagnosis of pancreatic carcinoma in situ.