Prevalence and Histomorphologic Patterns of High-Grade Prostatic Intraepithelial Neoplasia (HGPIN) In Prostatic Biopsies: A Ten-Year Retrospective Analysis from a North Central Nigerian Tertiary Health Institution

Background: High-grade prostatic intraepithelial neoplasia (HGPIN) represents the most likely precursor lesion to prostatic adenocarcinoma. Understanding its prevalence, age distribution, and association with other prostatic lesions is crucial for prostate cancer risk stratification and surveillance protocols in African populations where data remain limited.

Objective: This study aimed to determine the prevalence of HGPIN in prostatic biopsies at Jos University Teaching Hospital (JUTH), characterize the age-specific distribution, evaluate associated lesions, and assess temporal trends over a ten-year period.

Methods: A retrospective analysis was conducted on 1,450 prostatic specimens received at JUTH histopathology department from January 2000 to December 2009. All cases diagnosed with HGPIN were identified and analyzed for age distribution, associated prostatic lesions (nodular hyperplasia, chronic prostatitis, and carcinoma), histomorphologic patterns, and temporal trends. Statistical analysis included descriptive statistics and chi-square tests

Results: HGPIN was diagnosed in 41 of 1,450 prostatic specimens, yielding a prevalence of 2.8%. Patient ages ranged from 50 to ≥100 years with a mean age of 72.8 years and peak incidence in the 8th decade (70-79 years, 39.0%). The age-specific prevalence increased progressively with advancing age. Isolated HGPIN accounted for 34.1% (n=14) of cases, while 65.9% (n=27) occurred in association with other lesions: nodular hyperplasia (53.7%, n=22), chronic prostatitis (7.3%, n=3), and concurrent adenocarcinoma (4.9%, n=2). Annual HGPIN detection showed an increasing trend from 2000-2008, with peak detection in 2008 (12 cases), followed by a decline in 2009 (6 cases). The mean age for HGPIN patients (72.8 years) was comparable to that of prostatic adenocarcinoma patients, suggesting similar age-related oncogenic processes.

Conclusion: HGPIN prevalence of 2.8% in this North Central Nigerian population falls within the reported range for African populations. The peak occurrence in the 8th decade, frequent association with nodular hyperplasia (53.7%), and occasional concurrence with adenocarcinoma (4.9%) underscore the importance of careful histopathological evaluation and appropriate clinical follow-up. The increasing temporal trend suggests improved diagnostic awareness. These findings support the need for enhanced prostate cancer screening and surveillance protocols in Nigerian men, particularly those aged 60 years and above.