Background/purpose: The purpose of this study was to obtain the fundamental data necessary to discuss the appropriate operative mode for the resection of main-duct type intraductal papillary mucinous neoplasms (mIPMNs) of the pancreas.
Methods: In 23 patients who underwent total pancreatectomy with preoperative and postoperative diagnoses of mIPMN, the imaging studies and clinicopathological data were collected. The whole pancreatic specimen was histologically evaluated, and the distribution of atypical epithelium was mapped on a schema.
Results: Pathological examination of the specimens revealed that 18 patients had carcinoma in the pancreas; 8 patients had invasive lesions and one patient had lymph node metastasis. Specimens from 5 patients did not bear carcinoma lesions but had widespread borderline lesions in the pancreas. The mapping of lesions in the pancreatic specimens revealed that, at least, borderline or higher lesions were present both in the head and distal pancreas in all patients. In the majority of the specimens, lesions from adenoma to carcinoma co-existed on the same slide, and there were normal cell intervals between the malignant lesions.
Conclusion: We conclude that total pancreatectomy should be performed for mIPMN when dilatation of the main duct suggests possible spread of the lesion to the whole pancreas.