Benign Epithelial Tumors. Pathological findings of the specimen obtained from radical prostatectomy ((a) ×4, (b) ×40, and (c) ×400). The pathological finding was that epithelial cell proliferations without nuclear enlargement were frequently seen in the tumor of the prostate. It was just like benign epithelial hyperplasia and there was no evidence suggesting malignant tumor. Immunohistochemical pathology revealed that basal membranes were preserved by p63 staining and few cells were stained by p504S (d), suggesting that the tumor was not malignant. Prostatic Stromal Tumor of Uncertain Malignant Potential Which Was Difficult to Diagnose: Matsuyama S, Nohara T, Kawaguchi S, Seto C, Nakanishi Y, Uchiyama A, Ishizawa S - Case reports in urology (2015). Not altered. CC.