Frozen section biopsy correctly identified 58% of small testicular masses as benign, sparing those patients radical orchidectomy — with zero false negatives across 135 cases.
Journal: Histopathology | Published: 2025-11-20 | Type: Retrospective observational study | PMID: 41263775 Authors: Choiniere R, Boellaard WPA, Dinkelman-Smit M, van Leenders GJLH (Erasmus MC Cancer Institute, Rotterdam — a designated centre of expertise for rare urinary tract and testicular tumours) Funding/COI: Funding not listed. Authors declare no conflicts of interest.
When a small testicular mass is found on ultrasound, the standard reflex is radical orchidectomy — remove the whole testicle and sort it out later. This single-centre retrospective study of 135 frozen section excisional biopsies (FSEB) over 19 years argues that's often the wrong call. In 58% of cases, intraoperative pathology confirmed a benign diagnosis, and the testicle was left in place. The technique achieved 100% sensitivity and 96.3% specificity for malignancy, with no false negatives and only three false positives in the entire series.
This is a retrospective single-institution series with no control arm, which is appropriate for a diagnostic accuracy study of this type. The 19-year window (2005–2024) and 135 consecutive procedures at a dedicated centre of expertise give the dataset coherence, but also limit generalisability: results from a high-volume specialist centre with uropathologists available 90% of the time will not replicate in a district hospital where a general pathologist fields the intraoperative call. The authors acknowledge this directly.
Methodologically, grouping "favour malignant" with "malignant" and "favour benign" with "benign" is a clinically sensible decision (the surgical consequence is the same) but collapses nuance in the accuracy calculations. The three indeterminate cases were excluded from the concordance rate denominator, which is standard practice but worth noting — all three were ultimately benign, so including them would only improve the numbers.
The headline numbers — 100% sensitivity, 96.3% specificity, 81 testes preserved — are genuinely strong for an intraoperative diagnostic procedure. The absence of false negatives over 135 cases at a specialist centre is the most compelling finding: no patient had a malignancy missed and their testicle preserved when it shouldn't have been. The paper is what it claims to be: a well-executed retrospective accuracy study at a high-volume expert centre. What it cannot tell you is whether those numbers hold when FSEB is adopted more broadly, outside institutions with on-demand uropathology. That is the question the field still needs a prospective multicentre study to answer.