Testicular volume and testicular microlithiasis in boys with Down syndrome

Studies have suggested that testicular microlithiasis and Down syndrome are linked, yet a correlation remains unclear. We investigated the prevalence of testicular microlithiasis in patients with Down syndrome. We hypothesized that testicular microlithiasis is present at a higher rate in these patients. We further hypothesized that patients with Down syndrome have lower testicular volumes than normal age matched boys. We tested our hypothesis by ultrasound investigation in boys 0 to 18 years old with Down syndrome.

Testicular ultrasound was performed in 79 boys with Down syndrome. Mean patient age was 8.8 years (range 0.4 to 18.3). Testicular microlithiasis was assessed and testicular volume was measured according to the formula, π/6 × length × width × height.

Testicular microlithiasis was present in 18 boys (22.8%). It was diagnosed in 6 of 28 boys younger than 7 years (21.4%), in 6 of 28 boys 7 to 12 years (21.4%) and in 6 of 23 boys 12 years or older (26.1%). No significant difference was found in the prevalence of testicular microlithiasis between these 3 groups. Mean testicular volumes in patients with Down syndrome (2.19 ml) were significantly smaller than the normative values.

This study demonstrated a 22.8% prevalence of testicular microlithiasis in boys with Down syndrome, which is significantly increased compared to normative values. In addition, testis volume is significantly smaller in boys with Down syndrome compared to normative values.