Testicular mass frozen section examination: Pathological insights and diagnostic accuracy

Testicular frozen section examination on excisional biopsy (FSEB) is an underused pathological and surgical approach, considering the increasing number of small benign testicular lesions found on radical orchidectomy specimens. This study aims to determine the diagnostic accuracy of FSEB and to provide a pathological summary of the most frequent diagnoses and pitfalls.

We report the pathological findings and definitive outcome of 135 FSEB for small testicular masses performed between 2005 and 2024 in a single institute.

The median tumour size was 0.9 cm (Interquartile Range [IQR] 0.5-1.3 cm). The most common FSEB diagnoses were Leydig cell hyperplasia/tumour (n = 37; 28%) and seminoma (n = 36; 27%). On FSEB, benign diagnoses represented 58% of cases which allowed us to avoid 81 unnecessary radical orchidectomies. The sensitivity and specificity of FSEB for malignancy were 100% and 96.3%, respectively. Excluding three indeterminate cases on FSEB, the concordance rate was 97.7% (129/132). On definitive assessment, the majority of cases were benign (84/135, 62%) and 51 (38%) cases were malignant. The three indeterminate cases were ultimately confirmed as benign. There were three false-positive diagnoses of (favoured) malignancy and no false negatives.

FSEB is accurate for patient management of small testicular lesions, allowing us to save young men from unnecessary radical orchidectomy. We provide an in-depth overview of the most prevalent pathological diagnoses encountered.