Focal testicular lesions. Multiparametric us features and association with histopathology

NTRODUCTION AND OBJECTIVES: Testicular cancer represents the most common solid tumors in young men and malignant germ cell tumors constitute the majority of these masses. Orchiectomy is the treatment of choice for intratesticular masses. However, it is important to recognize those benign conditions for which orchiectomy is unwarranted because approximately 5-10% of all testicular masses are postoperatively identified as benign testicular lesions. Ultrasound features of solid scrotal tumors are often non-specific. US, however, identifies the lesion in the largest number of cases. Here, we evaluate the histopatologic features which determine echogenicity, echotexture, stiffness, and vascularity of different testicular masses. METHODS: 98 testicular lesions investigated with colour Doppler US for which histological specimens were available for review were enclosed. 47 lesions had also CEUS, 34 elastography. Imaging features were correlated with histological characteristics. RESULTS: Most testicular cancers were hypervascular at colour Doppler interrogation and with increased consistency at elastography. 6/22 hypovascular lesions with small vessels at colour Doppler interrogation were hypervascular at CEUS. Seminomas presented with lower echogenicity compared to other cancers, mixed tumors were heterogeneous. Irrespective of histotype, abundance of stroma was the main factor determining increased echogenicity. Other factors were hyalization, interleaved necrotic areas and tumor nests, athrophic changes of the surrounding parenchyma. Heterogeous appearance was observed in presence of different histotypes, calcifications, necrotic or fibrotic areas. Lesions were avascular at colour Doppler interrogation if vessels were lacking or were very small. In the latter case, they were vascularized at CEUS. Lesions with abundant stroma were hard at elastography, while necrotic changes caused soft or mixed appearance CONCLUSIONS: The different histological features of testicular lesions determine their sonographic appearance. US is highly sensitive for detection of testicular lesions, but specificity is low.The different US modes, if taken individually, are non-specific but if used together improve lesion characterization. Preoperative imaging and correct characterization of focal testicular lesions play a quite important role in guiding the surgical approach to these patients allowing the identification of testicular lesions amenable to treatment with testicular-sparing surgery