@article{oai:niigata-u.repo.nii.ac.jp:00006249, author = {Kurosaki, Ryo and Ajioka, Yoichi and Shirai, Yoshio and Watanabe, Hidenobu and Emura, Iwao and Ohta, Tamaki and Tsuchiya, Yoshiaki and Yamano, Miki and Hatakeyama, Katsuyoshi}, issue = {2}, journal = {Acta medica et biologica, Acta medica et biologica}, month = {Jun}, note = {Objectives: The present study aimed to clarify the definitions and histogenesis of ovarian-type stroma (OTS) in mucinous cystic neoplasms (MCNs) of the pancreas. Methods: Expression and density of cells positive for estrogen receptor (ER) and progesterone receptor (PR) were immunohistochemically studied in 16 MCNs (6 adenomas, 10 carcinomas), 22 intraductal papillary mucinous neoplasms (IPMNs), 10 common-type invasive ductal carcinomas (IDCs) and 24 non-neoplastic pancreatic tissues. Results: OTS comprised densely packed spindleshaped cells with round or elongated nuclei. Stromal cells were diffusely positive for ER and PR in all 16 MCNs. OTS-like stromal cells in IPMNs and IDCs were negative or only sporadically positive for ER or PR in all cases. In non-neoplastic pancreatic tissue, ER- and PR-reactive stromal cells were scattered sporadically irrespective of site in the pancreas (head, body or tail) or sex. Conclusions: OTS is an absolute marker for diagnosis of pancreatic MCNs and should be confirmed as ER- and PR-reactive on immunostaining in addition to findings from sections stained using hematoxylin-eosin. ER- and PR-reactive stromal cells may become hypersensitive to female sex hormone stimulation and start to proliferate and form OTS in the pancreas.}, pages = {57--65}, title = {Definition and Histogenesis of Ovarian-type Stroma in Mucinous Cystic Neoplasms of the Pancreas}, volume = {52}, year = {2004} }