Abstracts
1999 Digestive Disease Week

# 2141 SURGICAL MANAGEMENT OF INTRADUCTAL PAPILLARY-MUCINOUS TUMORS OF THE PANCREAS
Ryuichiro Doi, Ryo Hosotani, Koji Fujimoto, Takatomo Koshiba, Yoshiharu Miyamoto, Sanae Nakajima, Shoichiro Tsuji, Hiroyuki Kobayashi, Masayuki Imamura, Kyoto Univ, Kyoto Japan

Intraductal papillary-mucinous tumor (IPMT) is a type of pancreatic cystic neoplasms. IPMT consists of intraductal papillary-mucinous adenoma (benign IPMT), intraductal papillary-mucinous carcinoma (malignant IPMT), and borderline lesion, and the borderline lesion was regarded as benign in this study. Preoperative diagnosis of malignancy is difficult, the invasiveness and metastatic character are not well known. This study analyzed IPMT cases surgically treated in our institute. Preoperative imaging, mode of operation, clinical and histopathological findings were reviewed. Expression of p53, p21, Bax, Bcl-2, Bcl-X, Mcl-1, Cox-2 were immunohistochemically tested in IPMT and pancreatic ductal carcinoma samples. In 26 IPMTs, imaging of localization was correct in 79 % by CT, 56 % by US, 84 % by ERCP and 100 % by EUS. Evaluation of malignancy with EUS in 18 cases of IPMTresulted in sensitivity 100 %, specificity 29 %, and overall accuracy 53%. For 26 IPMTs, 17 PpPD, 2 PD, 2 DP, 3 TP, and 2 enucleations were performed. Eighteen cases were histologically malignant. Half of them were invasive beyond the border of the tumor. One case of malignant IPMT showed lymph node metastasis; the patient had no recurrence after PD with regional lymphadenectomy. No case was diagnosed as margin positive, however, 25 % cases showed a dysplasia with atypia in the epithelial cells of the cut edge of the pancreas. One case with negative atypia at the cut edge of the pancreas developed a recurrent tumor in the remnant pancreas. Immunohistochemistry showed significant expression in Bax (benign 14%, malignant 44%, ductal carcinoma 53 %), Bcl-X (57 %, 88 %, 90%), Mcl-1 (57 %, 88 %, 90%), Cox-2 (0 %, 27 %, 72%). Conclusions: EUS may be the best preoperative localization tool for IPMT. The preoperative diagnosis of malignancy is difficult, and 50 % of malignant IPMT was invasive, thus, pancreatectomy should be the choice of treatment, unless the tumor is pathologically diagnosed benign. Immunohistochemistry suggested that adenoma-carcinoma sequence could be present in the benign and malignant IPMT. Lymph node metastasis and intraductal distant invasion should be considered in the surgical treatment of these lesions.

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