Incidental Prostatic Adenocarcinoma in Open Prostatectomy Specimens: An Institutional Experience

Background: Prostatic diseases cause significant morbidity and mortality in African men. Most Nigerian patients presenting with huge prostate enlargement are availed open prostatectomy to relieve symptoms of prostatism. Some prostates removed for benign enlargement have indolent cancers that are only discovered after histopathological examination. The incidence of these incidental adenocarcinomas of the prostate varies widely.

Methodology: This was a 10-year retrospective review of open prostatectomy specimens received in the Department of Pathology, from January 2009 to December 2018. At grossing, a minimum of 6 cassettes were used depending on size, and tissue was taken from representative areas for microscopic examination. The data were analysed for the presence of, and the relationship between, incidental adenocarcinoma of the prostate and clinicopathological parameters in each case using relevant statistical tools in the SPSS version 23.

Results: Incidental adenocarcinoma of the prostate was found in 5.7% of 158 open prostatectomy specimens seen during the study period. High-grade prostatic intraepithelial neoplasm (HGPIN) was present in 1.9% of cases. Patients in the 7th and 8th decades accounted for 88.8% of all incidental adenocarcinomas. The mean weight of the excised glands was 89.8g (range10-500g). The weight of the prostate did not predict the diagnosis of incidental adenocarcinoma. In-hospital consultation accounted for 66.9% of open prostatectomy samples received in the department but the majority (72.7%) of incidental adenocarcinomas were seen in specimens from external consultations. The tumours were mostly ISUP grade group one tumours.

Conclusion: The rate of diagnosis of occult prostate cancer is low with the majority of the tumours being well differentiated. Organ weight had no relationship with histological diagnosis. Cases managed outside the teaching hospital were more likely to have incidental prostate cancer.