Diagnostic utility of immunohistochemical marker prostein for evaluation of primary and metastatic prostatic carcinomas

Abstract

Context: The diagnosis of prostatic adenocarcinoma on histopathology depends on architectural and cytomorphological features supported by immunohistochemistry (IHC). Though all the prostate markers show excellent specificity, the sensitivity and percentage positivity vary. Aims: In this study, we aim to study the expression of prostein in normal, benign, and malignant (primary and metastatic) lesions with particular emphasis on its utility in the differential diagnosis of poorly differentiated and metastatic prostatic adenocarcinoma along with a standard panel of IHC markers. Settings and Design: This was both a prospective and retrospective as well as descriptive and observational study. Subjects and Methods: All samples from patients with clinically suspected carcinoma prostate from both primary and metastatic sites from June 2015 to May 2016 were included in the study. Samples with difficulty in diagnosis on hematoxylin and eosin staining were subjected to a panel of IHC markers along with prostein. Statistical Analysis Used: Receiver operating curve analysis and Chi-square test. Results: Prostein showed a 100% sensitivity and specificity to identify normal prostatic epithelium, benign and premalignant lesions, and prostatic adenocarcinoma. Prostein showed a specificity of 100% in differentiating prostatic carcinoma from poorly differentiated urothelial carcinoma and in differentiating metastatic prostatic carcinoma from adenocarcinoma of nonprostatic origin. Conclusions: Prostein is a new and promising prostate-specific marker that showed slightly more sensitivity and specificity than prostate-specific antigen. Thus, adding prostein to the IHC panel will greatly improve the detection of poorly differentiated primary and metastatic lesions of the prostate.