Benign prostatic hyperplasia first develops in the
Periurethral transition zone
Peripheral zone
Central zone
Anterior fibromuscular stroma
Benign prostatic hyperplasia arises from submucosal glands of periurethral transitional zone with stromal proliferation and adenosis forming a nodular enlargement. It eventually compresses the peripheral zone glands into a false capsule and causes the appearance of typical 'lateral' lobes. Reference : page1345 Bailey and Love's sho practice of surgery 25th edition
Urology