In BPH most common lobe involved is -
Anatomical division of Prostate

Prostate has 5 lobes :

Anterior lobe

is a small isthmus connecting the two lateral lobes in front of the urethra.

Posterior lobe

it connect the two lateral lobes behind the urethra. It lies behind the median lobe and the ejaculatory ducts. Carcinomas are most common in this lobe.

Median lobe

lies behind the upper part of the urethra, in front of the ejaculatory ducts just below the neck of the bladder.
BHP arises in this lobe.

Lateral lobes

lie one on each side of the urethra.

Zonal or surgical division of Prostate

Prostate has 3 distinct zones


The peripheral zone (PZ) - accounts for 70% of volume of young adult prostate
The Central zone (CZ) - accounts for 25%
The transition zone (TZ) - accounts for 5%


Carcinoma of prostate arises most commonly in → the peripheral zone
Benign prostatic hyperplasia originates in → the transition zone
Lateral
Posterior
Median
Anterior