Title: Invasive carcinoma derived from intraductal papillary-mucinous tumors
Abstract: Akio Yanagisawa. Department of Pathology, Kyoto Prefectural University of Medicine, Kyoto, Japan SUIZOU 2003;18(6):703–707. It essential for “invasive carcinoma derived from intraductal papillary-mucinous tumors (IPMTs)” to meet the following two criteria for diagnosis. The intraductal areas of the cancerous lesion, except infiltrative parts, are histologically consistent with IPMT. The infiltrative parts are histologically adjacent, or compatible to be adjacent to the intraductal areas continuously. However, various lesions are currently included in the “invasive carcinoma derived from IPMTs” because the disease entity of IPMTs has changed. Therefore the diagnostic criteria of “invasive carcinoma derived from IPMTs” are not clear at prsent. The reason for the need to discriminate “invasive carcinoma derived from IPMTs” from other histological types of pancreatic carcinoma is to clarify the degree of its biological malignancy. Consistent with that need, “invasive carcinoma derived from IPMTs” should be classified into two histological subtypes based on the intraductal lesions forming IPMTs; P-type: papillary lesions that can be recognized macroscopically in pancreatic ducts, non-P type: macroscopically unrecognizable papillary lesions in pancreatic ducts. It is hoped that the degree of biological malignancy of “invasive carcinoma derived from IPMTs” can be accurately estimated by making a precise definition of IPMTs in the near future.