Pathology of Male Reproductive System 2

Pathology of Male Reproductive System 2

Professor Dr Ali Hassan Altimimi
Professor of pathology & histology MSc, PHD, MD(UK)

MALE REPRODUCTIVE SYSTEM

The Vas deferens (or ductus deferens)

The mucosa of the vas deferens forms low longitudinal folds. It is lined by a pseudostratified columnar epithelium. Similar to the epididymis, cells have long stereocilia. The lamina propria is unusually rich in elastic fibres. The muscularis is well developed (up to 1.5 mm thick) and consists of a thick circular layer of smooth muscle between thinner inner and outer longitudinal layers. The muscularis is the structure which makes the vas deferens palpable in the spermatic cord. The vas deferens is surrounded by an adventitia, which is slightly denser than usual.

Male Accessory Reproductive Glands
The accessory (or secondary) male sex glands consist of the seminal vesicles, the prostrate and the bulbourethral glands.

Prostate
The prostate is the largest accessory sex gland in en (about 2 × 3 × 4 cm). It contains 30 - 50 tubuloalveolar glands, which empty into 15 - 25 independent excretory ducts. These ducts open into the urethra. The glands are embedded into a fibromuscular stroma, which mainly consists of smooth muscle separated by strands of connective tissue rich in collagenous and elastic fibres. The muscle forms a dense mass around the urethra and beneath the fairly thin capsule of the prostrate.

The secretory alveoli of the prostate are very irregularly shaped because of papillary projections of the mucosa into the lumen of the gland. The epithelium is cuboidal or columnar. Basal cells are again present, and the epithelium may look pseudostratified where they are found. The secretory cells are slightly acidophilic and secretory granules may be visible in the cytoplasm. Small extensions of the apical cytoplasm into the lumen of the alveoli may represent cells which release their secretory products (secretion is apocrine/merocine). The secretion of the prostate contains citric acid, the enzyme fibrinolysin (liquefies the semen), acid phosphatase, a number of other enzymes and lipids.
The secretion of the prostate is the first fraction of the ejaculate.

The secretory ducts of the prostate are lined by a simple columnar epithelium, which changes to a transitional epithelium near the openings of the ducts into the urethra.

A characteristic feature of the prostate is the appearance of corpora amylacea in the secretory alveoli. They are rounded eosinophilic bodies. Their average diameter is about 0.25 mm (up to 2 mm). They appear already in the seventh month of foetal development. Their number increases with age - in particular past 50. They may undergo calcification. Corpora amylacea may appear in semen.

Macroscopically the prostrate can be divided into lobes, but they are inconspicuous in histological sections. In good histological sections it is possible to distinguish three concentric zones, which surround the prostatic part of the urethra.
• The peripheral zone contains large, so-called main glands, whose ducts run posteriorly to open into the urethra.
• The internal zone consists of the so-called submucosal glands, whereas

• the innermost zone contains mucosal glands.

Seminal Vesicles
The seminal vesicles develop from the vas deferens. Their histological organisation resembles to some extent that of the vas deferens. They are elongated sacs (about 4 cm long and 2 cm wide), which taper where they unite with the vas deferens. Each seminal vesicle consists of one coiling tube (about 15cm long). All the lumina visible in sections of the seminal vesicle are in continuity in the intact organ.

The mucosa shows thin, branched, anastomosing folds. The structure of the epithelium is variable appearing columnar or pseudostratified columnar (columnar cells and basal cells).
The lamina propria of the mucosa is fairly thin and loose. The muscularis consists of inner circular and outer longitudinal layers of smooth muscle.

Seminal vesicles were thought to store semen - hence there name. This turned out to be wrong. They are glands, whose secretion constitutes 60-70 % of the ejaculate. The secretory product of the columnar cell, which may be seen in the lumen of the seminal vesicles, is strongly acidophilic. It contains large amounts of fructose which the spermatozoa utilise as a source of energy. Furthermore, the secretion contains prostaglandins, flavins (yellow fluorescing pigment - of use in forensic medicine to detect semen stains) and several other proteins and enzymes.

The cocktail of compounds which is released by the seminal vesicles in addition to fructose has three main functions:

1. the formation of the sperm coagulum,

2. the regulation of sperm motility and

3. the suppression of immune function in the female genital tract.


The secretion of the seminal vesicles is the third fraction of the ejaculate (the spermatozoa are released with the second fraction - the contents of the vas deferens).

Pathology of Male Reproductive System 2
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Urethritis
- gonorrhea and NGU are important STDs
- Reiter s syndrome - the enigmatic triad of arthritis, conjunctivitis, and urethritis
- most pts are positive for HLA-B27

Peyronie s Disease
- proliferation of the dense fibrous tissue involving a portion of the fascia; this leads to curvature of an erection
- many pts require a penis prosthesis

Warts
- condyloma acuminata
- a papillary, keratinizing lesion caused by the sexually transmitted HPV (6); commonly occurs in the urethral meatus in men
- to spot HPV, wet the man s external genitalia with acetic acid and involved areas show white; it s now called androscopy
- condyloma latum
- groups of flat-topped lesions which may ooze serous fluid; caused by secondary syphilis; typically occur in skin folds

Cancer of the Penis
- almost all are variations of squamous cell carcinoma
- originates on glans and prepuce
- risk factors include phimosis, smegma, and balanoposthitis
- the strongest risk is infection with HPV-16
- males circumcised as infants almost never get cancer of the penis
- spreads to inguinal lymph nodes; five year survival is around 50% overall

Premalignant lesions of the Penis
- erythroplasia of Queyrat - a raised, velvety plaque on the uncircumcised glans or prepuce
- histologic study shows dysplasia of the squamous epithelium
- a minority of cases develop into squamous cell carcimona if not removed
- Bowen s disease
- carcinoma in situ of the skin, most often on the penis or scrotum in men
- some cases develop into invasive squamous cell carcinoma
- Bowenoid papulosis - multifocal carcinoma in situ, caused by HPV-16
- giant condyloma of Buscke-Lowenstein, or verrucous carcinoma - another HPV related, very ugly cauliflower like lesion; invasive cancer can breed here

Male Infertility
- spermatogenesis can be temporarily diminished or even stopped by a host of factors ranging from heavy drinking to anabolic steroids to alcoholism to bicycling
- obstruction of the sperm passages may be more amenable than the above to surgical help

Cryptochidism
- incomplete descent of the testis into the scrotal sac
- cryptorchid testes may be found anywhere along the normal route of descent
- the epididymis is likely to be malformed or at least elongated
- ectopic testes is less common; it may stray into the superficial inguinal region, penis, or femoral sheath
- failure of the testes to descend causes problems:
- the tubules will undergo atrophy and fibrosis, beginning in infancy
- there is an increased risk of torsion of the spermatic cord and gangrene of the testis
- the risk of germ cell cancer in undescended testes is 30X greater than normal
- most is idiopathic
- may be associated with diethyl-stilbesterol exposure