The Male Genital Tract

Figure 12.1

Normal external genitalia, gross

The normal appearance of the external male genitalia is shown here. Note the glans (∗) and prepuce (◼) (mucosal surfaces), but no foreskin in this circumcised penis. The shaft (♦) of the penis is covered by stratified squamous epithelium, as is the scrotum (□), with median (▲) raphe.

Figure 12.2

Epispadias, gross

This groove (▼) on the dorsal aspect of the penis extending for a short distance upward from the urethral meatus is an abnormality termed epispadias . This is an uncommon anomaly of variable severity. The example shown here is not severe. When severe and extensive along the dorsum of the penis, epispadias can lead to problems with urination and ejaculation. The opening may be partially constricted, predisposing to urinary tract infections. The foreskin of this uncircumcised penis is retracted here. This anomaly may be associated with other urinary tract anomalies and may be present along with cryptorchidism.

Figure 12.3

Hypospadias, gross

The urinary catheter seen here lies in a groove on the undersurface below the tip of the penis and enters the urethra. This abnormal opening is known as a hypospadias . Such an anomaly is present in approximately 1 in 300 male newborns, but it can lead to problems with urination and ejaculation, depending upon the severity (extent) of the defect. Constriction of the opening may be present, increasing the risk for urinary tract infections.

Figure 12.4

Balanoposthitis, gross

This glans penis surrounding the penile urethral meatus shows erythema and focal tan exudate, typical of a balanitis. The retracted foreskin (▶) is also acutely inflamed, a condition called posthitis . Together, this inflammatory condition is known as balanoposthitis . Infectious agents driving this process include Candida albicans, Gardnerella species, and pyogenic bacteria such as Staphylococcus aureus . Accumulated smegma (desquamated squamous epithelial cells and debris) beneath the foreskin predisposes to infection. Persistence of this inflammatory process predisposes to phimosis, a condition in which the prepuce cannot be retracted.

Figure 12.5

Penile intraepithelial neoplasia (PeIN), gross

Carcinoma in situ of the external male genitalia, PeIN, is historically termed Bowen disease when there is a plaque-like lesion (▲) as shown. This process is initially painless, but larger lesions may have erythema, ulceration, or crusting. The term erythroplasia of Queyrat describes PeIN with vascularity of mucosal surfaces (glans or prepuce). Bowenoid papulosis appears in younger patients as multiple, reddish-brown papular lesions. Microscopically, all these lesions have dysplastic squamous cells involving the full epithelial thickness without invasion through the basement membrane. Eventually, invasive squamous cell carcinoma occurs in approximately 10% of cases.

Figure 12.6

Squamous cell carcinoma, gross

This penectomy specimen contains a large invasive carcinoma (▲) that arose in the region of the head of an uncircumcised penis. This neoplasm is reddish tan and nodular, with an ulcerated surface. Such lesions are strongly associated with human papillomavirus infection, particularly types 16 and 18. Other factors, such as a history of smoking, lack of circumcision, and phimosis are also implicated. Most patients with this disease are older than 40 years. Most arise on the glans and prepuce. Denial and fear on the part of the patient may delay treatment.

Figure 12.7

Squamous cell carcinoma, microscopic

There are tongues of well-differentiated invasive carcinoma (▶) extending into the penile corpora cavernosum, with inflammatory cell infiltrates (▼). Similar to cervical cancer in women, penile carcinoma in younger men is most often correlated with human papillomavirus (HPV) infection seen in a third to half of cases, and the same types (16 and 18) are the most aggressive, with warty to basaloid features. Non-HPV-related carcinomas are usually low-grade. Lichen sclerosus, and phimosis with increased accumulation of smegma, can be risk factors in older men; penile cancer is rare in circumcised males. Lesions larger than 5 cm have a worse prognosis. Initial metastases occur most often to iliac and inguinal lymph nodes.

Figure 12.8

Verrucous carcinoma, microscopic

This well-differentiated form of squamous cell carcinoma displays extensive keratinization (♦). Also known as the Buschke-Löwenstein tumor, it is typically a large, exophytic, cauliflower-like lesion of the genital or perianal area, with nonhealing ulceration and sometimes fistulae and sinuses. The surface is warty (verrucous). It arises most often in men and immunocompromised patients, usually on the glans penis of uncircumcised men. A similar verrucous gross and histologic appearance of squamous cell carcinoma may be seen in the oral cavity, larynx, skin of the soles, and anal region.

Figure 12.9

Normal testis, gross

Here is a normal testis and adjacent structures, including the body of the testis (∗), epididymis (▪), and spermatic cord (▼). Note the presence of two vestigial structures, the appendix testis (♦) and the appendix epididymis (▲). The pampiniform plexus of veins (◼) lies posterior to the body of the testis. The normal testis descends down into the lower abdomen under the influence of müllerian-inhibiting substance. Final descent into the scrotum in the third trimester of fetal development is under the influence of increasing androgens; failure to descend results in cryptorchidism. The Leydig cells of a cryptorchid testis function normally, but the increased body temperature diminishes spermatogenesis.

Figure 12.10

Normal testis, microscopic

These seminiferous tubules contain numerous germ cells (∗). Sertoli (or “nurse”) cells are inconspicuous because their attenuated cytoplasm interdigitates with surrounding germ cells. Small dark oblong spermatozoa (▲) are in the center of the tubules because there is active spermatogenesis. The normal sperm count is 80 to 150 million/mL of ejaculate. Small nodular collections of pink Leydig cells (◼) are seen in the interstitium between the tubules, secreting testosterone under the influence of luteinizing hormone. Note the pale golden-brown pigment in the interstitium, which gives the testicular parenchyma its grossly pale-brown color. Sertoli cells secrete inhibin that feeds back on the adenohypophysis to inhibit release of follicle-stimulating hormone, which mediates spermatogenesis.

Figure 12.11

Cryptorchidism, gross

The testis seen on the left is atrophic, appearing small and pale white, whereas the testis on the right appears normal. This left testis did not descend into the scrotum during fetal development, but remained in the abdomen, a condition known as cryptorchidism , which is unilateral in 75% of cases. There may also be an inguinal hernia accompanying 10% to 20% of cases. The abnormal testicular position causes no pain, but predisposes to trauma, which does cause pain. Approximately 1% of male newborns have some initial failure of testicular descent.

Figure 12.12

Cryptorchidism, microscopic

Note the atrophic, small residual tubules (♦) with no spermatogenesis, and pale surrounding stroma. Leydig cells (not seen here) still retain their function. A cryptorchid testis fails to develop normal spermatogenesis, unless placed into the scrotum, because deterioration leading to the appearance shown begins by age 2. If unilateral, spermatogenesis in the remaining normal testis may prevent infertility. Cryptorchidism carries an increased risk for testicular carcinoma in either testis.

Figure 12.13

Testis, atrophy, gross

On the left is a normal testis, and the testis on the right has undergone atrophy. Bilateral atrophy may occur with various conditions, including chronic alcoholism, hypopituitarism, atherosclerosis, chemotherapy or radiation therapy, and severe prolonged illness. A cryptorchid testis also becomes atrophic. Inflammation with orchitis may lead to atrophy. Mumps, the most common infectious cause of orchitis, usually has a patchy and bilateral pattern of involvement that decreases the sperm count, but does not usually lead to sterility. Bilateral testicular atrophy may accompany Klinefelter syndrome (47,XXY karyotype). Testicular enlargement may occur with fragile X syndrome.

Figure 12.14

Testis, atrophy, microscopic

Here is focal atrophy (♦) of seminiferous tubules along with normal Leydig cells (∗) and residual normal tubules (◼) with active spermatogenesis. Mumps virus infection may be complicated by orchitis in one fourth to one third of cases. Generally, the orchitis is unilateral and patchy, so sterility following infection is uncommon. Other infectious causes of orchitis include echovirus, lymphocytic choriomeningitis virus, influenza virus, coxsackievirus, and arboviruses. In contrast, epididymitis is a more frequent cause of scrotal pain and swelling in men and is most likely to be the result of a sexually transmissible disease, such as Chlamydia trachomatis or Neisseria gonorrhoeae in younger men or gram-negative bacteria from urinary tract infection in older men.

Figure 12.15

Hydrocele, gross

Hydroceles are common accumulations of clear fluid within the sac of tunica vaginalis, which has a mesothelial-lined serosa. Hydrocele may occur in older men as a result of various inflammatory and neoplastic conditions. The external appearance of a testis with a hydrocele removed from the scrotum at autopsy is seen in the left panel . A cross-section through a frozen hydrocele (∗) removed at autopsy in the right panel shows the relationship of the fluid to the testis. The fluid in a hydrocele is a transudate that accumulates slowly, but can produce a mass effect and local discomfort. In many cases, the cause is not determined.

Figure 12.16

Hydrocele, gross

One diagnostic technique to detect a hydrocele is transillumination of the fluid-filled space with a light applied to the scrotum. This effect shown here resembles a lunar eclipse. The fluid collection typically occurs slowly and is not painful. A hydrocele must be distinguished from a true testicular mass, and transillumination may help in diagnosis because the hydrocele transilluminates, but a testicular mass is opaque to the light. Ultrasound examination provides a simple, noninvasive way of diagnosing scrotal masses.

Figure 12.17

Testis, varicocele, gross

A common cause of male infertility is a varicocele, a lesion that consists of prominent dilation of the pampiniform plexus of veins (◀) posterior to the testis, as shown by these prominent blue vessels. Most are asymptomatic and detected on palpation with the feel of “a bag of worms.” The increased blood flow makes this lesion a radiant heat device that increases the temperature of testicular tubules, inhibiting normal spermatogenesis. It can be present to some degree in up to 20% of men and 40% of infertile men.

Figure 12.18

Testicular torsion, gross

This testis (▲) has undergone hemorrhagic infarction following torsion, which is a medical emergency. It occurs when sudden twisting of the spermatic cord cuts off the venous drainage, leading to severe scrotal pain. Torsion in adolescents often occurs when there is greater mobility from abnormal incomplete testicular descent or lack of a scrotal ligament. Perinatal torsion occurs rarely and for no apparent reason. Immediate treatment by surgically untwisting and suturing the cord in place to prevent future torsion prevents infarction and loss of function. Sometimes, just the little appendix testis undergoes torsion to produce acute pain.

Figure 12.19

Testicular torsion, microscopic

In this case, torsion of the testis has proceeded to hemorrhagic infarction with no viable cells within the seminiferous tubules. Note the pale outlines of the residual tubules (∗), but there is loss of nuclear detail and the interstitium is hemorrhagic. The most common signs and symptoms include a red, swollen scrotum and acutely painful testicle without evidence of trauma. Nausea and vomiting are common. Doppler ultrasound scan be helpful in showing lack of blood flow, confirming the diagnosis.

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Dec 29, 2020 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on The Male Genital Tract
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