Porth's Essentials of Pathophysiology, 4e

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Genitourinary and Reproductive Function

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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.

SUMMARY CONCEPTS (continued)

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 ■■ 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.