title: Mucinous cystic tumor of the pancreas: immunohistochemical assessment of "ovarian-type stroma".
abstract: The new histopathological classification of exocrine pancreatic tumors by the World Health Organization, now includes "ovarian-type stroma" ("OS") in the definition of mucinous cystic tumor of the pancreas (MCT-P). This study investigated the clinicopathological findings of the MCT-P according to WHO classification and scrutinize the function of "OS" in MCT-P immunohistochemically. Thirty-four cases of MCT-P (28 adenomas, 2 borderline tumors and 4 adenocarcinomas) were examined clinicopathologically. The "OS" of 34 MCTs-P were studied immunohistochemically and compared with the stroma of 10 mucinous cystic tumors of the ovary (MCTs-O), 10 conventional pancreatic carcinomas and 6 normal ovaries. Almost all 34 MCTs-P were located in the body-tail of the pancreas of middle-aged women. Histologically the "OS" cells exhibited luteinization in 11/34 (32.4%). Immunohistochemically, both "OS" cells and the stromal cells in MCT-O showed similar positivity rates; calponin (34/34 and 9/10), h-caldesmon (28/34 and 8/10), alpha-inhibin (29/34 and 9/10), estrogen-receptor (21/34 and 6/10) and progesterone-receptor (28/34 and 9/10, respectively). Some neoplastic epithelial cells of MCT-P were positive for human chorionic gonadotropin (hCG) (21/34, 61.8%). This study indicates the predominance of MCT in the distal pancreas of middle-aged women. Furthermore, the immunohistochemical and histological results demonstrate that the "OS" of MCT-P and the stroma of MCT-O share the same characteristics. The results also suggested that the hCG produced by the neoplastic epithelium probably plays an important role in the luteinization of the stroma of MCT-P. We therefore conclude there is a possibility that MCT-P originates from the left remnant primordial gonadal cells which migrated to the pancreatic anlage during the early development of the fetus.
authors.affiliation: Department of Anatomic Pathology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Izumo
authors.forename: Koji
authors.initials: K
authors.lastname: Yamaguchi
authors.forename: Takashi
authors.initials: T
authors.lastname: Eguchi
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Nishiyama
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Hirotoshi
authors.initials: H
authors.lastname: Yonemasu
authors.forename: Takashi
authors.initials: T
authors.lastname: Yao
authors.forename: Masao
authors.initials: M
authors.lastname: Tanaka
authors.forename: Masazumi
authors.initials: M
authors.lastname: Tsuneyoshi
mesh_terms: D002288:Adenocarcinoma, Mucinous / Q000737:chemistry / Q000378:metabolism / Q000473:pathology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis; D002135:Calcium-Binding Proteins / Q000378:metabolism; D002148:Calmodulin-Binding Proteins / Q000378:metabolism; D018291:Cystadenoma, Mucinous / Q000737:chemistry / Q000378:metabolism / Q000473:pathology*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008840:Microfilament Proteins; D008875:Middle Aged; D010053:Ovary / Q000473:pathology; D010179:Pancreas / Q000473:pathology; D010190:Pancreatic Neoplasms / Q000737:chemistry / Q000378:metabolism / Q000473:pathology*; D011379:Prognosis; D017154:Stromal Cells / Q000473:pathology*; D000096985:Calponins
chemical_list: D014408:Biomarkers, Tumor; D002135:Calcium-Binding Proteins; D002148:Calmodulin-Binding Proteins; D008840:Microfilament Proteins; D000096985:Calponins