Lateral part of prostate

The lateral part of the prostate (lateral lobe) refers to one of the paired lobes of the prostate gland situated on either side of the prostatic urethra, as described in the classical lobar classification system originally proposed by Lowsley in the early 20th century.

Historical and Anatomical Context

The concept of prostatic lobes was first introduced by Lowsley based on examinations of human embryos. He proposed that the prostate should be divided into five lobes: an anterior lobe, a posterior lobe, two lateral lobes, and one middle lobe. The lateral lobes are the largest of these divisions and form the bulk of the glandular prostate on each side of the urethra. They are composed of glandular and fibromuscular stromal tissue, and in the adult prostate they constitute the majority of the palpable gland on digital rectal examination.

Relationship to Modern Zonal Anatomy

The lobar classification has been largely superseded in clinical and pathological practice by McNeal's zonal anatomy, which divides the prostate into the peripheral zone (~70% of glandular tissue), central zone (~25%), transition zone (~5%), and anterior fibromuscular stroma. In this modern framework, the lateral lobes correspond primarily to the peripheral zone - the posterolateral glandular tissue extending from the base to the apex - with contributions from the transition zone anteromedially. The Terminologia Anatomica (the international standard for anatomical nomenclature) retains the term "lobe" only for the right and left lobes and the variable middle lobe, and uses the term "lobule" for subdivisions (superomedial, anteromedial, inferoposterior, and inferolateral lobules on each side).