S-100A1 Is a Reliable Marker in Distinguishing Nephrogenic Adenoma From Prostatic Adenocarcinoma

Abstract

Nephrogenic adenoma is a benign lesion that may occur at any site of the genitourinary tract, usually in association with previous urothelial injuries. Although its pathogenesis is still debated, recent studies seem to confirm its derivation from renal tubular epithelium, rather than from a metaplastic process of urothelium. In addition to its uncertain origin, there can be diagnostic difficulty in distinguishing nephrogenic adenoma from prostatic adenocarcinoma, particularly with lesions arising in the prostatic urethra. So far, immunohistochemical stains are often needed to make such a distinction, and several markers have been proposed, often with controversial results. S100A1 is a calcium binding protein that has been recently reported to be expressed in renal tubular cells and in a subset of renal cell neoplasms. Alpha-methylacyl-CoA racemase (AMACR), a recently identified prostate cancer marker, has also been found to be expressed in renal tubules and in some renal epithelial neoplasms. In this study, we investigated the expression of S100A1 and AMACR in 18 nephrogenic adenomas and in 100 prostatic adenocarcinomas. A strong and distinct cytoplasmic or nucleocytoplasmic staining of S100A1 was found in 17 out of 18 cases of nephrogenic adenoma (94%), but never in prostatic adenocarcinoma. In contrast, AMACR expression was detected in 14 of 18 nephrogenic adenomas (78%) and in 96 of 100 prostatic adenocarcinomas (96%). We conclude that (1) S100A1 is a specific and sensitive immunohistochemical marker to differentiate nephrogenic adenoma from prostatic adenocarcinoma; (2) AMACR immunostaining does not seem to be a useful marker in distinguishing between these 2 lesions; (3) given that both S100A1 and AMACR have been reported to be expressed in renal tubular cells and in a subset of renal cell neoplasms, our findings confirm the histogenetic relationship between nephrogenic adenoma and renal tubular epithelium.

Interaction of S100A1 with LATS1 promotes cell growth through regulation of the Hippo pathway in hepatocellular carcinoma

“…S100A1 was found to be differentially expressed in clear cell renal cell carcinoma and papillary renal cell carcinoma, and the differential expression may be a potentially useful marker to differentiate the chromophobe renal cell carcinoma from renal oncocytoma ( 7 , 8 ). S100A1 can also be used to differentiate other tumors ( 21 – 25 ).…”

The Application of Immunohistochemical Biomarkers in Urologic Surgical Pathology

“…The reported expression of P504S in nephrogenic adenoma ranges from 58% to 100%, and most nephrogenic adenomas were also CK903 negative. 86,188,189 The similarity in certain morphologic features and the P504Sþ/CK903À immunoprofile of nephrogenic adenoma make the distinction between prostate carcinoma from nephrogenic adenoma challenging. Additional immunomarkers, especially PSA, PAX2 (or PAX8), and CK7 can help to differentiate nephrogenic adenoma from prostate carcinoma.…”

Nephrogenic Adenoma of the Urinary Tract

“…46 Moreover, recent studies demonstrated a strong and distinct cytoplasmic or nucleocytoplasmic staining of S100A1 in 94% (17 of 18) of the NAs examined. 47…”