A 4-Antibody Panel Including 34βE12, CD10, AMACR and CD57 Can Reliably Distinguish Different Cystic Renal Tumors
Mariana M Padilha, Ming Zhou, Karen Streator Smith, Paula Carver, Cristina Magi-Galluzzi. Cleveland Clinic, Cleveland, OH; NYU Medical Center Tisch Hospital, New York, NY
Background: The distinction of multilocular cystic renal cell carcinoma (MLCRCC) from other cystic renal neoplasms can be challenging at times when based solely on hematoxylin and eosin-stained sections. We evaluated the potential use of few immunohistochemical markers in the differential diagnosis of cystic renal tumors.
Design: Archival tissue from 15 MLCRCC, 15 cystic nephromas (CN)/mixed epithelial and stromal tumors (MEST), and 9 tubulocystic carcinomas (TCC) were retrieved from our surgical pathology files and stained for CK7, 34βE12, CD10, AMACR, CA9 and CD57. Extent of immunohistochemical staining was scored as diffuse (>75% of tumor cells positive), patchy (25-75%), focal (<25%), and negative. Focal and negative staining was combined.
Results: Staining pattern is summarized in table 1. All CN/MEST, 94% of MLCRCC and 67% of TCC showed diffuse or patchy staining for CK7. All MLCRCC displayed negative or focal staining for 34βE12; 40% of the CN/MEST and 22% of TCC showed patchy staining. CD10 was negative or focal in 74% of MCRCC and 87% of CN/MEST, but positive in all TCC. AMACR was negative in 93% of MLCRCC, and positive in 89% of TCC and 54% of CN/MEST. CA9 was positive in all MLCRCC, 80% of CN/MEST and 78% of TCC. CD57 was negative or focal in all MCRCC, but positive in 60% of CN/MEST and 67% of TCC. A staining pattern of 34βE12(-)/CD10(-)/AMACR(-)/CD57(-) distinguished most MLCRCC from CN/MEST and TCC (sensitivity 73%, specificity 92%, positive predictive value [PPV] 85% and negative predictive value [NPV] 85%). A staining pattern of CD10(+)/AMACR(+)/CD57(+)/34βE12(-) demonstrated to be highly specific for TCC (sensitivity 67%, specificity 97%) with high PPV (86%) and NPV (91%) in the differential diagnosis with CN/MEST and MLCRCC. On the other hand a staining pattern of 34βE12 (+/-)/CD10(+/-)/AMACR(+/-)/CD57(+) favored the diagnosis of CN/MEST.
Conclusions: CA9 and CK7 are of limited value in the differential diagnosis of cystic renal tumors. A four-antibody panel including 34βE12, CD10, AMACR and CD57 can reliably distinguish MLCRCC, CN/MEST and TCC.