title: E-cadherin-negative acinar cell carcinoma of the pancreas: report of a case showing a solid pseudopapillary growth pattern.
abstract: E-cadherin expression patterns in acinar cell carcinomas (ACCs) of the pancreas have not been well documented. Herein, we present a hitherto undescribed case of E-cadherin-negative ACC with a solid pseudopapillary growth pattern in a 65-year-old man. We used an antibody against the extracellular domain of E-cadherin. As a further unusual status in ACC, faint β-catenin expression was observed in the cytoplasm of carcinoma cells. Morphological distinction from a solid pseudopapillary neoplasm (SPN) of the pancreas might be problematic in such a case, because of their similarities concerned with the growth pattern and E-cadherin negativity. Without nuclear accumulation of β-catenin, a diagnosis of SPN was almost excluded. Immunoreactivity for trypsin and BCL10 made an accurate diagnosis of ACC to this case. The tumor recurred 10 months post-surgery as rapidly enlarging masses in the liver, presumably indicating the aggressiveness of the E-cadherin-negative phenotype among ACCs.
authors.affiliation: Department of Pathology, Shizuoka Saiseikai General Hospital, Shizuoka, Japan. stajima-tky@umin.ac.jp.
authors.forename: Shogo
authors.initials: S
authors.lastname: Tajima
authors.affiliation: Department of Cell Biology and Anatomy, Hamamatsu University School of Medicine, Shizuoka, Japan.
authors.forename: Michihiko
authors.initials: M
authors.lastname: Waki
authors.affiliation: Department of Surgery, Fujieda Municipal General Hospital, Shizuoka, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Azuma
authors.affiliation: Department of Pathology, Fujieda Municipal General Hospital, Shizuoka, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Koda
authors.affiliation: Department of Gastroenterology, Fujieda Municipal General Hospital, Shizuoka, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Ohata
mesh_terms: D000368:Aged; D015703:Antigens, CD; D015820:Cadherins / Q000378:metabolism*; D018267:Carcinoma, Acinar Cell / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology*; D002291:Carcinoma, Papillary / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology*; D049109:Cell Proliferation; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology*
chemical_list: D015703:Antigens, CD; C513384:CDH1 protein, human; D015820:Cadherins
keywords: Acinar cell carcinoma; E-cadherin; Pancreas; Solid pseudopapillary; β-catenin