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Updated: Apr 14, 2026
Isolation of Glomeruli and In Vivo Labeling of Glomerular Cell Surface Proteins
Published on: January 18, 2019
Immunoexpression of napsin A in renal neoplasms
Bing Zhu1, Stephen M Rohan2, Xiaoqi Lin3
1Department of Pathology, Northwestern Memorial Hospital, Feinberg School of Medicine, Northwestern University, 251 E. Huron St., Galter Pavilion 7-132 F, Chicago, IL, 60611, USA. zhubing8590@hotmail.com.
Background:
Immunohistochemistry (IHC) for napsin A has been widely used to support a diagnosis of lung adenocarcinoma with high sensitivity. In this study, we evaluated immunoreactivity for napsin A in a broad spectrum of renal neoplasms by using tissue microarrays (TMA).
Methods:
Duplicate TMA of 159 surgically excised renal neoplasms of various types were constructed. IHC for napsin A was performed on TMAs with appropriate positive and negative controls.
Results:
Napsin A was expressed in Acquired cystic disease associated renal cell carcinoma (RCC) (2/2, 100.0%), chromophobe RCC (5/45, 11.1%), clear cell RCC (10/23, 43.5%), clear cell papillary RCC (9/19, 47.4%), metanephric adenoma (3/3, 100.0%), oncocytoma (13/23, 56.5%), and papillary RCC (31/37, 83.8%). Expression of napsin A was not seen in mucinous tubular and spindle cell carcinoma (0/1, 0.0%), TFE/MITF RCC 0/1, 0.0%), and urothelial carcinoma (0/6, 0.0%).
Conclusions:
Napsin A is expressed in both common and rare sub-types of renal neoplasms with variable sensitivity. Based on our results, napsin A is not specific for lung adenocarcinoma. When a metastatic carcinoma of unknown primary is positive for napsin A, the differential diagnosis should include tumors of both renal and lung origin.
Virtual Slides:
The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/9558727831304717 .
