La biopsia dirigida por micro-ultrasonido permite la detección de adenocarcinoma prostático de mínima extensión (≤ 1 mm): hallazgos clínico-patológicos de una serie consecutiva

Objective: To determine the frequency and clinicopathological characteristics of cases of minimal-extent prostate adenocarcinoma (linear extent ≤ 1 mm) identified in prostate biopsies performed using micro-ultrasound (Micro-US). Materials and methods: This retrospective, observational, descriptive study included 604 unique patients who underwent prostate biopsy using an approach incorporating micro-ultrasound (Micro-US) between January 2024 and December 2025. Patients were included if a single focus of prostatic acinar adenocarcinoma with a maximum linear extent of ≤1 mm was identified in the examined biopsy cores. Case selection was based on the maximum linear extent of the tumor focus, as measured histologically. Results: Twelve cases of minimal-extent prostatic acinar adenocarcinoma were identified among the 604 patients studied. Ten cases (83.3 %) were detected in targeted biopsy cores and two (16.7 %) in systematic biopsy cores. The mean patient age was 64.3 years, and the median prostate-specific antigen (PSA) level was 6.3 ng/mL. The mean linear extent of adenocarcinoma was 0.74 mm (range, 0.12–1.0 mm). Multiparametric magnetic resonance imaging was available in three cases, with findings classified as PI-RADS 3 in one case and PI-RADS 4 in the remaining two. Conclusions: Minimal-extent prostatic acinar adenocarcinoma (≤ 1 mm) was identified in 1.99 % (12/604) of the patients. Most cases were detected in targeted biopsy cores. The identification of these minimal-extent foci highlights that very small-volume tumors can be recognized histopathologically in prostate biopsies obtained using procedures incorporating Micro-US.