Nuclear expression of E-cadherin in solid pseudopapillary tumors of the pancreas.
BACKGROUND
Solid pseudopapillary tumors of the pancreas are rare and have recently been shown to harbor mutations of the beta-catenin gene with resultant nuclear localization of beta-catenin protein to the nucleus. Moreover, there is a close relationship between beta-catenin and E-cadherin.


OBJECTIVE
To explore the protein expression of E-cadherin in a series of solid pseudopapillary tumors of the pancreas.


METHODS
Eighteen cases of solid pseudopapillary tumors of the pancreas.


METHODS
The cases were studied using a tissue microarray that was constructed as follows: for each case, 4 to 14 cores measuring 1.0 mm each were drilled from the blocks. Tissue cores from normal pancreas were used as controls and for orientation purposes.


METHODS
The slides were stained with the following commercially available antibodies: CD10, CD56, vimentin, alpha-1-antitrypsin, alpha-1-antichymotrypsin, neuron-specific enolase, chromogranin, synaptophysin, beta-catenin and E-cadherin.


RESULTS
All the tumors were CD10, vimentin, alpha-1-antitrypsin and alpha-1-antichymotrypsin diffusely positive (50% or more of the tumor cells staining) and CD56 showed focal positivity in all cases with 5-10% of tumor cells displaying immunolabeling. All cases were negative for chromogranin and synaptophysin. All 18 cases displayed cytoplasmic and nuclear localization of beta-catenin protein. Similarly, E-cadherin protein was localized to the nucleus in all 18 cases, with loss of the characteristic membranous decoration of cells.


CONCLUSIONS
This study is the first demonstration of aberrant nuclear localization of E-cadherin protein in solid pseudopapillary tumors of the pancreas. Whilst the exact mechanism is not know and nuclear E-cadherin is not related to tumor aggression, this staining pattern may be of diagnostic value in concert with beta-catenin staining.
Serra
Stefano
S
Department of Pathology, University Health Network/Toronto Medical Laboratories, Toronto, ON, Canada. runjan.chetty@uhn.on.ca
Salahshor
Sima
S
Fagih
Mosa
M
Niakosari
Firouzeh
F
Radhi
Jasim M
JM
Chetty
Runjan
R
D000293:Adolescent; D000328:Adult; D019002:CD56 Antigen / Q000032:analysis; D015820:Cadherins / Q000032:analysis*; D002291:Carcinoma, Papillary / Q000737:chemistry* / Q000473:pathology; D002467:Cell Nucleus / Q000737:chemistry*; D002648:Child; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D015260:Neprilysin / Q000032:analysis; D010190:Pancreatic Neoplasms / Q000737:chemistry* / Q000473:pathology; D051176:beta Catenin / Q000032:analysis
D019002:CD56 Antigen; D015820:Cadherins; D051176:beta Catenin; D015260:Neprilysin