Prostatic adenocarcinoma and prostatic intraepithelial neoplasia: A tale of the autopsy model in a Nigerian tertiary hospital Dele Eradebamwen Imasogie, Akhator Terence Azeke Nigerian Journal of Surgical Sciences 2017 27(2):41-46 Introduction: The frequency of clinical prostatic adenocarcinoma and high-grade prostatic intraepithelial neoplasia (HGPIN) in a certain population could be similar to the prevalent model of latent adenocarcinoma as well as to the frequency and extent of HGPIN. The aim of this prospective postmortem study is to determine the prevalence of occult adenocarcinoma and HGPIN and contrasting same with the existing clinical model in the same environment. Subjects and Methods: Adult individuals who died from ailments unrelated to diseases of the prostate glands were the target population using a calculated minimum sample size of 72 cases. The partial sampling method was employed. Sections were assessed for prostatic adenocarcinoma and HGPIN. The biodata and clinical diagnosis were obtained from stored records. Results: Seven patients had occult adenocarcinoma representing 8.1% of the study population of 86 cases. Their median age was 60 years. It had a peak incidence in the sixth decade, with a prevalence of 42.85% in the subset of the study population who had the disease. Gleason's grade 3 and score 6 were the most frequent grades and scores encountered in this study. Those with occult adenocarcinoma were graded International Society of Urological Pathologist (ISUP) 1 using the ISUP grade group system. There were five cases of HGPIN in this study. Their median age was 54 years. It had a peaked incidence in the eighth decade. Conclusion: There exists a subset of the population with occult prostatic adenocarcinoma and HGPIN. These subclinical prostatic lesions may become clinically apparent if these patients had lived long enough, and hence, the prostate should be considered as a possible primary site of metastatic carcinoma because of this concept “occult adenocarcinoma.”