title: Clusterin is highly expressed in pancreatic endocrine tumours but not in solid pseudopapillary tumours.
abstract: OBJECTIVE
  Clusterin is a sulphated glycoprotein, implicated in many processes, including tumorigenesis. Several studies have reported its overexpression in many human neoplasms, including prostatic and pancreatic adenocarcinoma, but its expression has not been described previously in other pancreatic tumours. Our aim was to investigate the expression of clusterin by immunohistochemistry in 30 endocrine pancreatic tumours (ENTs) and 22 solid pseudopapillary tumours (SPPTs) to document its potential in differential diagnosis, and the possible correlation between this expression and clinicopathological parameters.
  
  
  RESULTS
  Cytoplasmic positivity was scored qualitatively (weak, moderate or strong immunoreactivity) and quantitatively on a four-tiered scale. The pattern of immunoreactivity (cytoplasmic, secretory or Golgi pattern) was also assessed. Except for scattered tumour cells in five cases, all SPPTs were negative, while all ENTs showed strong immunoreactivity in a variable proportion of tumour cells. Neither the reactivity score nor the pattern of immunoreactivity was correlated with tumour size, vascular permeation, perineural invasion or lymph node metastasis.
  
  
  CONCLUSIONS
  The expression of clusterin in all ENTs is of interest and could be an additional useful marker in the differential diagnosis with SPPTs. However, the lack of correlation between clusterin expression and clinicopathological parameters rules out a role as a predictive marker for endocrine tumour aggressiveness.
authors.affiliation: Department of Pathology, St Antoine Hospital, Paris, France. najat.mourra@sat.ap-hop-paris.fr
authors.forename: N
authors.initials: N
authors.lastname: Mourra
authors.forename: A
authors.initials: A
authors.lastname: Couvelard
authors.forename: E
authors.initials: E
authors.lastname: Tiret
authors.forename: S
authors.initials: S
authors.lastname: Olschwang
authors.forename: J-F
authors.initials: JF
authors.lastname: Flejou
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism; D018273:Carcinoma, Islet Cell / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D002291:Carcinoma, Papillary / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D051152:Clusterin / Q000378:metabolism*; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000378:metabolism* / Q000473:pathology / Q000601:surgery
chemical_list: D014408:Biomarkers, Tumor; C495242:CLU protein, human; D051152:Clusterin