Testicular microlithiasis: what does it mean clinically?

To review our current practice of follow-up for boys with testicular microlithiasis (TM), an uncommon condition characterized by calcification within the seminiferous tubules, detected by ultrasonography (US); TM has been associated with both benign and malignant conditions of the testes but the natural history of TM in children remains unclear.

All boys diagnosed with TM over a 14-year period were included in this study. A search of the radiology database was carried out using the keywords 'testicular microlithiasis' and 'testicular calcification'. A retrospective case-note review was then used to determine age at diagnosis, presenting symptoms, indication for testicular US, outcome and follow-up. We also searched Medline/PubMed, using the same keywords for published data on TM from 1970 to 2006.

Over the study period 711 testicular scans were taken in 623 patients; seven cases (1.1%) of TM were identified. The mean (range) age at presentation was 12 (7-15) years. The presenting symptoms were testicular pain (three), undescended testes (two), hydrocele (one) and asymptomatic scrotal swelling (one). In five cases the TM was bilateral and in two a solitary kidney was identified. Only one patient had tumour markers measured (beta-human chorionic gonadotrophin and alpha-fetoprotein) and these were within normal limits. On yearly US follow-up, the TM was less prominent in one patient, unchanged in four and two were lost to follow-up. Three patients are currently on yearly US follow-up while two are under the care of adult general surgeons. The analysis of reports published to date indicated that malignancy only develops when TM is associated with other predisposing factors.

There is no convincing evidence that TM alone is premalignant. However, when it accompanies other potentially premalignant features we recommend annual US follow-up.