Testicular microlithiasis in Japanese male infertility patients: Clinical implications for predicting future testicular malignancy.

Abstract

e15579 Background: Testicular microlithiasis (TM) is commonly diagnosed by scrotal ultrasonography (US) in which it appears as multiple, small, uniform, echogenic foci without shadowing, scattered randomly throughout the testicular parenchyma. It is also prevalent in several urologic diseases including subfertility and testicular germ cell tumor. TM has been reported to be associated with carcinoma in situ (CIS) and the development of second testicular germ cell tumor (TGCT) after contralateral orchiectomy treatment for primary TGCT; however, no prospective studies have investigated the relationship between the detection of TM in patients without TGCT and future development of TGCT. In the present study, therefore, we investigated the prevalence of TM in the testes of male infertility patients and unilateral TGCT patients to determine if TM could be a predictor of future germ cell tumor in such patients. Methods: A total of 1,139 subfertile patients (296 with nonobstructive azoospermia, 58 with obstructive azoospermia, and 785 with oligozoospermia) and 22 unilateral testicular germ cell tumor patients were enrolled in the study. Prevalence of testicular microlithiasis according to testicular ultrasonography was compared between patients, and development of testicular germ cell tumors was monitored for at least 3 years. All patients were fully informed about the study, and their prior consent was obtained according to the recommendation of the institutional ethics committee. Results: The prevalence of TM was significantly higher in unilateral TGCT patients (40.9%) than in subfertile men (8.6%). No infertile patients without TM developed TGCT but one infertile patient with TM developed TGCT (seminoma) during follow up. One seminoma patient with TM in his remaining testis went on to developed testicular seminoma 3years after primary surgery. Conclusions: Testicular microlithiasis is more common in testicular germ cell tumor patients than in subfertile men. Since TM could be a surrogate marker for future TGCT in both patient populations, TM patients are recommended to perform careful self-checking of the testes and periodical testicular ultrasonography.