Neck of glans penis

The neck of the glans penis (Collum glandis) refers to the constricted region at the base of the glans penis where it joins the penile shaft. This area is defined by two closely related anatomical landmarks:

• The corona (corona glandis): the semi-circular, raised prominence or ridge on the dorsal aspect of the glans that projects beyond the shaft.

• The coronal sulcus (sulcus coronarius, also simply called the "sulcus"): the circumferential groove or furrow that lies just proximal to the corona and demarcates the glans from the penile shaft.

Together, the corona and the coronal sulcus form the "neck" of the glans penis the narrowed transitional zone between the wider glans distally and the penile shaft proximally. In a flaccid, uncircumcised penis, this region is typically covered by the foreskin. In young boys, the demarcation between the foreskin and glans at this level is often not fully formed, which may prevent retraction of the foreskin below the corona.

Histologically, the glans penis is composed of stratified squamous epithelium overlying a dense connective tissue layer (lamina propria) that is continuous with the tunica albuginea of the corpus spongiosum. The corpus spongiosum expands distally to form the glans, embedding the distal tips of the corpora cavernosa. The neck region is notable for a high density of sensory nerve endings, particularly genital end bulbs, which are most numerous in the corona and near the frenulum.

Clinical significance: The neck of the glans is an important surgical landmark in circumcision, penile reconstructive surgery, and the staging of penile carcinoma, where the depth of invasion through the anatomic levels of the glans (epithelium → lamina propria → corpus spongiosum → corpus cavernosum) is prognostically significant.