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U N I T 1 1
Genitourinary and Reproductive Function
Disorders of the Penis, the
Scrotum andTestes, and the
Prostate
The male genitourinary system is subject to structural
defects, inflammation and infection, and neoplasms, all
of which can affect urine elimination, sexual function,
and fertility.
Disorders of the Penis
Disorders of the penis include congenital defects (dis-
cussed in the section on disorders of childhood), acute
and chronic inflammatory conditions, Peyronie disease,
priapism, and neoplasms.
Inflammation and Infection
The term
balanitis
refers to local inflammation of the
glans penis and
balanoposthitis
to inflammation of the
glans penis and overlying prepuce.
13–15
The condition
may result from trauma, irritation, or infection caused
by a wide array of organisms. Among the most com-
mon infectious agents are
Candida albicans
, anaerobic
bacteria, and pyogenic bacteria. A significant number
of inflammatory conditions are caused by sexually
transmitted infections (see Chapter 41). Balanitis due
to
C. albicans
infection may be a presenting feature or
result from poorly controlled diabetes mellitus.
Acute superficial balanoposthitis is characterized
by erythema of the glans and prepuce. An exudate in
the form of malodorous discharge may be present. It
usually is encountered in males with phimosis (a tight
foreskin) or a large, redundant prepuce that interferes
with cleanliness and predisposes to bacterial growth
in the accumulated secretions and smegma (i.e., debris
from the desquamated epithelia). Extension of the ery-
thema and edema may lead to extensive scarring and
a condition called
phimosis
, in which the prepuce can-
not be retracted easily over the glans prepuce. When
the stenotic prepuce is forcibly retracted over the glans
prepuce, the circulation can be compromised causing
congestion, swelling, and pain, a condition known as
paraphimosis
.
Balanitis xerotica obliterans
is a chronic, sclerosing,
atrophic process of the glans penis that occurs in uncir-
cumcised men. It is clinically and histologically simi-
lar to the lichen sclerosus that is seen in women
15
(see
Chapter 40). Typically, the lesions consist of grayish-
white plaques on the surface of the glans penis and the
prepuce. The foreskin is thickened and fibrous and is
not retractable. Although balanitis xerotica obliterans
was once considered a benign condition, it is now rec-
ognized as a precancerous state.
16
Treatment measures
include circumcision and topical or intralesional injec-
tions of corticosteroids.
13
Peyronie Disease
Peyronie disease involves a localized and progressive
fibrosis of unknown origin that affects the tunica albu-
ginea (i.e., the tough, fibrous sheath that surrounds
the corpora cavernosa) of the penis. It is named after
Francois de la Peyronie, who in 1743 described a patient
who had “rosary beads of scar tissue to cause upward
curvature of the penis during erection.”
17,18
The disor-
der is characterized initially by an inflammatory pro-
cess that results in dense fibrous plaque formation. The
plaque usually is on the dorsal midline of the shaft,
causing upward bowing of the shaft during erection
(Fig. 39-7). Some men may develop scarring on both
the dorsal and ventral aspects of the shaft, causing the
penis to be straight but shortened or have a lateral bend.
The fibrous tissue prevents lengthening of the involved
area during erection, making intercourse difficult and
painful. The disease usually occurs in middle-aged or
elderly men.
The manifestations of Peyronie disease include painful
erection, bent erection, and the presence of a hard mass
at the site of fibrosis. Approximately two thirds of men
complain of pain as a symptom. The pain is thought to
be generated by inflammation of the adjacent fascial tis-
sue and usually disappears as the inflammation resolves.
■■
The function of the male reproductive system
is under the negative feedback control of
the hypothalamus and the anterior pituitary
gonadotropic hormones—FSH and LH.
Spermatogenesis is initiated by FSH, and the
production of testosterone is regulated by LH.
■■
The male sex act involves erection, emission,
ejaculation, and detumescence.The physiology
of these functions involves a complex interaction
between autonomic-mediated spinal cord
reflexes, higher neural centers, and the
vascular system. Erection is mediated by the
parasympathetic nervous system and emission
and ejaculation by the sympathetic nervous
system.
■■
Erection is a neurovascular process involving
the autonomic nervous system, the somatic
nervous system by way of the pudendal nerve,
the vascular system, and the sinusoidal spaces
of the corpora cavernosa. Erectile dysfunction is
defined as the inability to achieve and maintain
an erection sufficient to permit satisfactory
sexual intercourse. It can be due to psychogenic
factors, organic disorders, or mixed psychogenic
and organic conditions. Erectile dysfunction is
now recognized as a marker for cardiovascular
disease and men with the disorder should be
evaluated for coexisting vascular disease.
SUMMARY CONCEPTS
(continued)
