Incidence of testicular microlithiasis.

In adults polytopic intratubular calcifications of the testes are rare. Known as testicular microlithiasis, they manifest themselves in a characteristic echo pattern on sonography with high-frequency transducers (5 to 10 MHz). This consists of multiple echogenic specks in an otherwise normal testicular parenchyma. In a retrospective analysis of 1,710 testicular sonograms of adults, bilateral intratesticular microliths were found in 11 cases (0.6%). In 5 of them, the microliths were associated with a testicular tumor. One patient with a tumor in the contralateral testis had undergone radiotherapy and another one presented with hypogonadism. Four patients with noncontributory histories presented with varicocele or epididymal cyst. Sonographic findings were confirmed histologically in 6 patients. Multiple intratubular calcifications were found in all of them. The pathogenesis of testicular microliths is still poorly understood. Their clinical relevance is unclear, but their incidence in adults appears to be higher than reported in the literature.