Skip Navigation LinksHome > March 2014 - Volume 22 - Issue 3 > Diagnostic and Prognostic Role of Immunohistochemical Expres...
Applied Immunohistochemistry & Molecular Morphology:
doi: 10.1097/PAI.0b013e31828ef24e
Research Articles

Diagnostic and Prognostic Role of Immunohistochemical Expression of Napsin-A Aspartic Peptidase in Clear Cell and Papillary Renal Cell Carcinoma: A Study Including 233 Primary and Metastatic Cases

Xu, Bin MD, PhD*; Abourbih, Samuel MD; Sircar, Kanishka MD; Kassouf, Wassim MD; Aprikian, Armen MD; Tanguay, Simon MD; Brimo, Fadi MD*

Collapse Box


Napsin-A aspartic peptidase (napsin-A) is an aspartic protease that is predominantly expressed in the proximal renal tubules and type II pneumocytes of the lung. Recently, napsin-A was reported to be present in a proportion of renal cell carcinomas (RCCs). However, the utilization of napsin-A immunohistochemistry as a routine diagnostic tool for RCC, and the correlation of the level of napsin-A expression with histologic features have not yet been established. In the current study, using tissue microarrays composed of primary and metastatic RCCs, napsin-A expression was demonstrated in 86 of 222 (39%) clear cell RCCs (CRCCs) and 16 of 21 (76%) papillary RCCs (PRCCs), with a strong and diffuse staining pattern observed in PRCCs and a relatively weak and focal positivity in CRCCs. Compared with primary CRCCs, a comparable proportion of metastatic CRCCs retained napsin-A expression (45/132, 34%), suggesting the potential utility of napsin-A in the evaluation of metastatic tumors. The expression of napsin-A was also found to be inversely correlated to aggressive local tumor characteristics, such as advanced pathologic stage and high Fuhrman nuclear grade. We conclude that napsin-A may be a valuable immunohistochemical marker in the diagnosis of RCCs, particularly PRCC.

© 2014 Lippincott Williams & Wilkins, Inc.


Article Tools


Article Level Metrics

Search for Similar Articles
You may search for similar articles that contain these same keywords or you may modify the keyword list to augment your search.