A cross-sectional cadaveric study of the correlation between genital organ measurements, serum testosterone, and serum prostate-specific antigen levels in Japanese male subjects.

Association of organ sizes in the genitalia have long been a topic of interest for the general public. However, factors such as selection bias, embarrassment, and invasive testing have hindered studies on living individuals. We obtained measurements of penile size, testicular weight, and prostate weight, and conducted related serum testing on 63 Japanese male adults who died of unexpected reasons and underwent autopsy from 2009 to 2013. Micropenis was seen in 7 subjects (11.1%) as determined by flaccid penile length. Penile measurements were mainly correlated with body weight, testicular weight with age and body mass index, and prostate weight with age and serum prostate-specific antigen level. No correlation was detected between testosterone and any genital organ measurements. Interestingly, penile circumference showed no correlation to any of the penile length measurements. Prostate weight showed a significant positive correlation with penile circumference, penile stretched length, and testicular weight. Although the direct clinical implications are unclear, utilizing autopsy provided insight into genital organ measurements free of patient selection bias and other disadvantages of live patient testing. With a larger sample size, autopsy studies may be of use to future adjustment of nomograms.