Clinical Outcomes of Incidental Small Foci of High-Grade Prostate Cancer Identified in Transurethral Resections of Prostate (TURP) Specimens.

High-grade acinar prostatic adenocarcinoma, characterized by a Gleason score exceeding 7 (Grade Groups 4 or 5), is associated with a poorer prognosis, including increased risks of recurrence and metastasis. While much research has focused on high-grade prostate cancer diagnosed via needle biopsy, little is known about the clinical implications of incidental high-grade prostate cancer found in transurethral resection of the prostate (TURP) specimens. This study reviews the clinical outcomes of 18 patients with high-grade prostate cancer involving ≤ 5% of TURP tissue, diagnosed between 2014 and 2024. Inclusion criteria included a first-time diagnosis of prostate cancer, acinar adenocarcinoma with a Gleason score of 8 or higher, and involvement of less than 5% of TURP tissue. Clinical data, including age, prostate-specific antigen levels, treatment type, and follow-up, were recorded. The cohort had a mean age of 75 years, and the follow-up period averaged 34 months. Histopathologic findings included Grade Groups 4 and 5 tumors, with intraductal prostatic carcinoma (IDC) found in 5 patients. Treatment varied, with 39% receiving hormonal therapy and radiotherapy, 33% opting for active surveillance, and 11% undergoing radical prostatectomy. Notably, 17% of patients experienced disease progression, with IDC present in all of these patients. Despite low-volume disease (≤ 5% of specimens), a notable proportion of patients developed metastasis or died from prostate cancer, challenging the traditional view that incidental findings in TURP are of limited consequence. Patients with IDC appear especially vulnerable to adverse outcomes.