The prevalence of testicular microlithiasis in an asymptomatic population of men 18 to 35 years old

Purpose: Testicular microlithiasis is an imaging entity of the testicle thought to be a marker of testicular cancer. To our knowledge the prevalence of testicular microlithiasis in an asymptomatic population at risk for testicular cancer is unknown. We report an ultrasound screening study done to establish the prevalence of testicular microlithiasis in an asymptomatic population. Materials and Methods: Healthy men 18 to 35 years old from the annual Army Reserve Officer Training Corps training camp volunteered for study. A screening genitourinary history was obtained, and physical examination and screening scrotal ultrasound were performed. We defined testicular microlithiasis as more than 5 high intensity signals on ultrasound with each signal larger than 2 mm. We categorized testicular microlithiasis into microcalcifications that were scant-5 to 25 per side, moderate-greater than 25 per side but no areas of near confluence and too numerous to count. In all subjects with testicular microlithiasis tumor markers were also measured. Results: Of 1,504 evaluated men with a mean age of 22.4 years, 84 (5.6%) had testicular microlithiasis, including 45 of 1,053 white (4%), 21 of 149 black (14.1%), 6 of 71 Hispanic (8.5%), 3 of 54 Asian or Pacific Island (5.6%) men and 9 of 174 (5.2%) who claimed no race affiliation. Tumor markers were normal in all subjects with testicular microlithiasis. Conclusions: Testicular microlithiasis occurs in more than 5% of healthy young men. In contrast, testicular cancer develops in 3/1.00,000 to 5/100,000 men or 1,000-fold less often. The relative prevalence of testicular microlithiasis with respect to testicular cancer, increased prevalence in minorities, bilateral distribution, and inverse geographic distribution of men with testicular microlithiasis and testicular cancer represent evidence against an association of the 2 conditions. This study indicates that testicular microlithiasis is a common finding in asymptomatic men that may not be related to testicular cancer.