title: Immunocytochemical study of the expression of mesothelin in fine-needle aspiration biopsy specimens of pancreatic adenocarcinoma.
abstract: Mesothelin is a potential marker of pancreatic adenocarcinoma that was recently identified by serial analysis of gene expression. We evaluated the sensitivity and specificity of mesothelin as a marker of pancreatic adenocarcinoma on destained Papanicolaou (Pap) smears and unstained cellblocks from 28 patients using a monoclonal antibody to mesothelin. Intensity and proportion of staining was semiquantitatively graded on a scale of 1-3, and as 0%, 1 to <10%, 10-50%, or >50%. Positive staining for mesothelin was seen in 64% of the direct smears and in 36% of cell block sections. Focal positivity for mesothelin was noted in benign pancreatic tissue in one of 10 cases. Staining was most often focal (<50% of cells) in both direct smears and cell block sections. The overall sensitivity and specificity of mesothelin as a marker for pancreatic adenocarcinoma were 68% and 90%, respectively. Sensitivity was higher in Pap smears than in cell block sections (64% versus 36%). The presence of occasional mesothelin expression in benign tissue, its very focal expression in malignant tissue may limit the utility of mesothelin as a marker of pancreatic adenocarcinomas in fine-needle aspiration (FNA) specimens.
authors.affiliation: Department of Cytopathology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
authors.forename: Amy C
authors.initials: AC
authors.lastname: Baruch
authors.forename: Huamin
authors.initials: H
authors.lastname: Wang
authors.forename: Gregg A
authors.initials: GA
authors.lastname: Staerkel
authors.forename: Douglas B
authors.initials: DB
authors.lastname: Evans
authors.forename: Rosa Frances
authors.initials: RF
authors.lastname: Hwang
authors.forename: Savitri
authors.initials: S
authors.lastname: Krishnamurthy
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis* / Q000473:pathology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044963:Biopsy, Fine-Needle; D005260:Female; D058851:GPI-Linked Proteins; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism*; D000090204:Mesothelin; D008875:Middle Aged; D010179:Pancreas / Q000473:pathology; D010190:Pancreatic Neoplasms / Q000175:diagnosis* / Q000473:pathology*; D065006:Papanicolaou Test; D014626:Vaginal Smears
chemical_list: D058851:GPI-Linked Proteins; D008562:Membrane Glycoproteins; D000090204:Mesothelin