High resolution sonography in diagnosing testicular neoplasms: clinical significance of false positive scans.

We describe the use of high resolution real-time ultrasound to evaluate scrotal masses. From August 1980 to September 1984, 249 patients underwent scrotal ultrasound using high resolution real-time scanners with 10 mHz. transducers to evaluate scrotal abnormalities. The ultrasound diagnosis was consistent with a testicular neoplasm in 20 patients. Pathological and surgical confirmation was available in all 20 patients. Only 10 of 20 patients had malignant tumors, whereas 10 had benign lesions (false positive rate of 50 per cent). Testicular lesions producing false positive studies were principally hypoechoic in 8 patients and hyperechoic in 2. Testicular neoplasms characteristically were hypoechoic with or without focal hyperechoic areas. There was 1 false negative ultrasound study. Our results suggest that radical orchiectomy should not be performed indiscriminately in all patients with testicular lesions that are sonographically suspicious for neoplasm. In selected cases with hyperechoic sonographic features associated frequently with benign testis lesions open testicular biopsy and a testis-sparing operation may be indicated.