Diagnostic Value of Cytokeratin 34 beta E12 (Ck34βE12) and α-Methylacyl-CoA racemase (AMACR) Immunohistochemical Expression in Prostatic Lesions

Abstract

Scan to discover online Background & Objective: Some prostatic lesions contain small suspicious foci for prostatic carcinoma in which the morphological features are equivocal. Two immunohistochemical markers namely, cytokeratin 34 beta E12 (Ck34βE12) and α-Methylacyl-CoA racemase (AMACR), were evaluated in these lesions for a definitive diagnosis and avoiding misdiagnosis or overdiagnosis of prostatic carcinoma. Methods: A total of 90 paraffin embedded blocks of prostatic tissue were selected and categorized into three groups as follows: 50 cases of benign prostatic hyperplasia (BPH), 20 cases of prostatic carcinoma, and 20 cases of benign prostatic lesions with suspicious foci labeled as ASAP (atypical small acinar proliferation) that occupy not more than 5% of the lesion. These cases were revised for histopathological diagnosis and stained with two immunohistochemical markers: Ck34βE12 and AMACR. Results: While 92.9% of BPH were positive for Ck34βE12, 96% of prostatic carcinoma were negative for this marker (P=0.0001). Regarding AMACR, 92.9% of BPH cases were negative, but 92% of prostatic carcinoma cases were positive for this marker (P=0.0001). Out of 20 cases of BPH, 15 cases containing suspicious foci showed Ck34βE12+/AMACR-(diagnosis: benign), but 5 cases were Ck34βE12-/AMACR+, for which the diagnosis changed to prostatic carcinoma (P=0.04). Conclusion: Immunohistochemical staining with Ck34βE12 and AMACR improved the diagnostic performance and increased confidence level for establishing definite diagnosis in cases with suspicious foci, in which the morphological features were equivocal. This could help to avoid misdiagnosis or overdiagnosis of prostatic carcinoma that would eventually improve the management of the patient and subsequently the prognosis.

Evaluation of automatic discrimination between benign and malignant prostate tissue in the era of high precision digital pathology

“…In view of recent studies, the three simple rules proposed by Sabata et al are not likely to be able to account for possible heterogeneity of staining of benign and malignant tissue. It is possible that benign glands may show some weak to moderate AMCAR expression and, on the other hand, it is not a necessity for prostate cancer to be AMCAR–positive (especially high grade subtypes can be negative, and inter- and intratumoral heterogeneity can occur) [ 42 , 43 ]. For benign tissue, e.g., tissue of atypical adenomatous hyperplasia (AHH), high expression of AMCAR has been reported in up to more than 50% of the cases [ 44 ].…”