Transperineal biopsy is a biopsy procedure in which a sample of tissue is removed from the prostate for examination under a microscope. The sample is removed with a thin needle that is inserted through the skin of the perineum (between the scrotum and anus) and into the prostate. Transperineal biopsy is a biopsy procedure in which a sample of tissue is removed from the prostate for examination under a microscope. The sample is removed with a thin needle that is inserted through the skin of the perineum (between the scrotum and anus) and into the prostate. This article incorporates public domain material from the U.S. National Cancer Institute document 'Dictionary of Cancer Terms'.