Carefully selected intratesticular lesions can be safely managed with serial ultrasonography. 
To evaluate a policy of conservative non-operative management for incidental, impalpable, < 1 cm, intratesticular pathology.  We retrospectively reviewed all scrotal ultrasonograms within an 8-year period to identify all radiological lesions of < 1 cm within the testis.  All palpable lesions and those accompanied by elevated tumour markers or disseminated malignancy were managed surgically.  The remaining incidentally detected lesions were followed with a protocol of serial ultrasonography (US).  Of 1544 scans reviewed, 12 (0.8%) lesions suitable for observational management were identified.  The mean (range) age of the patients was 54 (34-76) years.  The indication for US was suspected epididymitis in five, contralateral epididymal cyst in five and infertility in two patients.  The mean (range) size of the lesion was 4.9 (1.5-9.8) mm.  Three anechoic lesions were consistent with intratesticular cysts, and each was followed with no change to a mean (range) follow-up of 26 (12-48) months.  Eight hypoechoic lesions were followed to a mean of 34 (4-72) months, and only one showed growth on repeat US after an interval of 4 months, and was diagnosed as a 1.0-cm seminoma after orchidectomy.  One hyperechoic lesion remains unchanged at 6 months of follow-up.  Supported by previous reports suggesting that most testis lesions of < 1 cm are benign, we managed a series of carefully selected intratesticular lesions conservatively, the behaviour in most being in keeping with benign pathology.