Penis is the site of many congenital anomalies only some of which have clinical significance.
A variety of abnormalities occur in size and form, including aplasia or hypoplasia; hypertrophy; duplication; pin-hole meatus, and more commonly, hypospadias, epispadias, and phimosis.
Hypospadias and Epispadias:
Malformation of the urethral groove and urethral canal causes abnormal openings either on the ventral surface of the penis (hypospadias) or on the dorsal surface (epispadias). These may be associated with other urogenital malformations, including undescended testes.
Its clinical significance is as follows:
i) Constriction of this abnormal opening may produce partial urinary obstruction with spread of infection from penile urethra to bladder and the entire urinary tract.
ii) When the orifice is situated at the base of the penis, normal ejaculation and insemination are hampered or totally blocked producing sterility in men.
Phimosis is the inability to retract the prepuce because of an abnormally small preputial orifice. It may arise as a primary developmental defect but is more commonly secondary to inflammatory scarring of the prepuce. Phimosis predisposes to secondary infection and carcinoma, due to chronic accumulation of secretions and other debris under the foreskin.
Paraphimosis is the abnormal painful swelling of the glans penis after forceful retraction of a phimotic prepuce. It may cause urethral obstruction.
Circumcision is effective therapy for phimosis and the complication of balanoposthitis.