Parvati Ramchandani

The increasing detection of small testicular lesions by ultrasound (US) in adults can lead to unnecessary orchiectomies. This article describes their nature, reviews the available literature on this subject and illustrates some classical lesions. We also suggest recommendations to help characterization and management. The ESUR scrotal imaging subcommittee searched for original and review articles published before May 2015 using the Pubmed and Medline databases. Key words used were ‘testicular ultrasound’, ‘contrast-enhanced sonography’, ‘sonoelastography’, ‘magnetic resonance imaging’, ‘testis-sparing surgery’, ‘testis imaging’, ‘Leydig cell tumour’, ‘testicular cyst’. Consensus was obtained amongst the members of the subcommittee, urologist and medical oncologist. Simple cysts are frequent and benign, and do not require follow up or surgery. Incidentally discovered small solid testicular lesions detected are benign in up to 80 %, with Leydig cell tumours being the most frequent. However, the presence of microliths, macrocalcifications and hypoechoic areas surrounding the nodule are findings suggestive of malignant disease. Asymptomatic small testicular lesions found on ultrasound are mainly benign, but findings such as microliths or hypoechoic regions surrounding the nodules may indicate malignancy. Colour Doppler US remains the basic examination for characterization. The role of newer imaging modalities in characterization is evolving. • Characterization of testicular lesions is primarily based on US examination. • The role of MRI, sonoelastography, contrast-enhanced ultrasound is evolving. • Most small non-palpable testicular lesions seen on ultrasound are benign simple cysts. • Leydig cell tumours are the most frequent benign lesions. • Associated findings like microliths or hypoechoic regions may indicate malignancy.

The subcommittee on scrotal imaging, appointed by the board of the European Society of Urogenital Radiology (ESUR), have produced guidelines on imaging and follow-up in testicular microlithiasis (TML). The authors and a superintendent university librarian independently performed a computer-assisted literature search of medical databases: MEDLINE and EMBASE. A further parallel literature search was made for the genetic conditions Klinefelter’s syndrome and McCune-Albright syndrome. Proposed guidelines are: follow-up is not advised in patients with isolated TML in the absence of risk factors (see Key Points below); annual ultrasound (US) is advised for patients with risk factors, up to the age of 55; if TML is found with a testicular mass, urgent referral to a specialist centre is advised. Consensus opinion of the scrotal subcommittee of the ESUR is that the presence of TML alone in the absence of other risk factors is not an indication for regular scrotal US, further US screening or biopsy. US is recommended in the follow-up of patients at risk, where risk factors other than microlithiasis are present. Risk factors are discussed and the literature and recommended guidelines are presented in this article. • Follow up advised only in patients with TML and additional risk factors. • Annual US advised for patients with risk factors up to age 55. • If TML is found with testicular mass, urgent specialist referral advised. • Risk factors – personal/ family history of GCT, maldescent, orchidopexy, testicular atrophy.