| [ Summary ] |
Pathological specimens of pancreatic endocrine tumors are discussed. This type of tumor was formerly classified into functional and non-functional, but recent immunohistochemical studies have revealed various aspects of endocrine and exocrine secretion of the tumor cells. In our study, according to the hormones secreted, this type of tumor was classified into three divisions, i.e., non-functional (which shows a positive reaction to endocrine markers, but not to any endocrine hormone), monoclonal(which shows a positive finding for only one endocrine hormone), and polyclonal (which shows positive findings for more than two endocrine hormones). Furthermore, regarding another aspect of exocrine secretion, this tumor is classified into two divisions, i.e., pure type (which shows a positive reaction to only endocrine markers), and combined type (which shows positive reactions to both endocrine and exocrine markers). To our knowledge, the polyclonal and combined types of this tumor have malignant potential, and this classification is anticipated to be useful for investigating malignancy. |