Potential Utility of GATA3 Immunoexpression and HPV Status in the Differential Diagnosis of Urothelial vs Squamous Cell Carcinomas of Distal Penile Urethra
Jeong S Han, George J Netto, Stephen Lee, Nilda Gonzalez-Roibon, Hillary Ross, Rajni Sharma, Antonio L Cubilla, Alcides Chaux. Johns Hopkins University, Baltimore, MD; Instituto de Patologia e Investigacion, Asuncion, Paraguay
Background: Squamous cell carcinoma (SCC) and urothelial carcinoma (UC) occur as primary tumors of the distal penile urethra, possibly reflecting histogenesis from the native squamous or urothelial mucosa at this site. As there may be a considerable morphologic overlap between the two tumor types, the utility of GATA3, a transcription factor that has been rencently used as a marker of urothelial differentiation, and human papillomavirus (HPV) status was evaluated in the differential diagnosis of the two entities.
Design: We retrieved 6 cases originally classified as primary urothelial carcinoma of distal urethra from our surgical pathology archives. All H&E sections were retrieved and reviewed by 2 urologic pathologists on the study. Medical records were also reviewed. Extension from other urologic sites was clinically excluded in all cases. Whole routine representative sections were stained for GATA3 (BioCare, GATA3 clone L50-823) using standard immunohistochemistry techniques. In situ hybridization for high-risk HPV (HR-HPV) was also performed in all cases. In addition, GATA3 immunoexpression was evaluated in a tissue microarray (TMA) containing 38 cases of SCC of the penile glans.
Results: In the TMA section, all 38 cases of penile glans SCC were negative for GATA3. Based on the morphologic review, GATA3 immunohistochemistry, and HR-HPV in situ hybridization, the 6 distal urethral tumors were reclassified as shown in Table 1.
|Case No.||Age||Reclassified Diagnosis||GATA3||HR-HPV|