[Evaluation of the expression and significance of Claudin-5 and CD99 in solid-pseudopapillary neoplasms and neuroendocrine tumors of pancreas].
OBJECTIVE
To investigate the expression of endothelium tight junction protein Claudin-5 and intercellular adhesion molecule CD99 in solid-pseudopapillary neoplasms (SPN) and neuroendocrine tumors of pancreas (P-NET), and their significance in the differential diagnoses.


METHODS
Immunohistochemical staining of Claudin-5 and CD99 was performed in 37 cases SPN and 21 cases of P-NET.


RESULTS
Membranous Claudin-5 expression was observed in all cases of SPN but was absent in all cases of P-NET. The difference was significant (P < 0.01). In SPN, 91.9% (34/37) of the cases displayed paranuclear dot-like immunoreactivity for CD99; in contrast, 61.9% (13/21) of the cases of P-NET displayed membranous staining (P < 0.01). There was a positive association between the expression of Claudin-5 and CD99 in SPN (r = 0.421,P = 0.001).


CONCLUSIONS
Although the macroscopic and microscopic features of SPN are quite characteristic, they may not allow confident differentiation from P-NET in all cases, especially when these characteristics are not classical. If necessary, immunostaining for Claudin-5 and CD99 can help to differentiate between these entities.
Department of Pathology, the Second Affiliated Clinical Hospital of Harbin Medical University, Harbin 150086, China.
Hong-yan
HY
Zheng
Yan-hong
YH
Shi
Li-fang
LF
Zhang
Ying-zhun
YZ
Chen
D000071443:12E7 Antigen; D000293:Adolescent; D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000378:metabolism*; D002291:Carcinoma, Papillary / Q000378:metabolism / Q000473:pathology*; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D002648:Child; D062507:Claudin-5 / Q000378:metabolism*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018358:Neuroendocrine Tumors / Q000378:metabolism / Q000473:pathology*; D010190:Pancreatic Neoplasms / Q000378:metabolism / Q000473:pathology*; D012189:Retrospective Studies; D019108:Tight Junctions / Q000378:metabolism; D055815:Young Adult
D000071443:12E7 Antigen; D015703:Antigens, CD; C061828:CD99 protein, human; C107466:CLDN5 protein, human; D015815:Cell Adhesion Molecules; D062507:Claudin-5