The male reproductive system consists of external and internal organs responsible for hormone production, spermatogenesis, and delivery of sperm. Understanding normal anatomy, performing regular self-examination, and recognizing abnormalities are essential for early detection of conditions including testicular cancer, infertility, and sexual dysfunction.

Male reproductive anatomy includes the testes, epididymis, vas deferens, seminal vesicles, prostate, and penis. Source: Unsplash.

Anatomy Overview

The testes produce sperm and testosterone. The epididymis stores and matures sperm. The vas deferens transports sperm from the epididymis to the ejaculatory duct. The seminal vesicles produce 60-70% of seminal fluid (rich in fructose and prostaglandins). The prostate produces 20-30% of seminal fluid (containing PSA, acid phosphatase, and zinc). The bulbourethral glands (Cowper glands) produce pre-ejaculate fluid that lubricates and neutralizes urethral acidity. The penis serves both urine elimination and sperm delivery. The scrotum regulates testicular temperature through contraction and relaxation.

The male reproductive system produces sperm through spermatogenesis in the testes and transports them through a network of ducts. Source: Unsplash.

Testicular Self-Examination

Testicular self-examination (TSE) should be performed monthly, ideally after a warm bath or shower when the scrotal skin is relaxed. Stand in front of a mirror and examine the scrotum for swelling or asymmetry. Support the scrotum in the palm of your hand. Roll each testicle gently between your thumb and fingers. Feel for the epididymis — the soft, cord-like structure on top and behind each testicle. Palpate the spermatic cord (vas deferens) above the testicle. Note the normal size, shape, and consistency: firm but not hard, smooth, and oval.

What to Look For

A painless lump or enlargement of the testicle is the most common sign of testicular cancer. A dull ache or heavy sensation in the scrotum may also indicate cancer. Sharp pain suggests torsion, trauma, or infection. Scrotal swelling may indicate a hydrocele, varicocele, or hernia. Tenderness in the epididymis suggests epididymitis. A “bag of worms” sensation above the testicle indicates a varicocele. An absent testicle may be due to cryptorchidism (undescended testicle) or prior orchiectomy.

★ Key Concept

Testicular cancer is the most common cancer in men aged 15-35, but it has a cure rate exceeding 95% when detected early. Monthly self-examination takes only 60 seconds. Most testicular cancers are first discovered by men themselves or their partners. The goal is to recognize any change from baseline — enlargement, a new lump, or a change in texture. If you notice anything unusual, see your healthcare provider promptly. Not all lumps are cancer (many are benign conditions like epididymal cysts or hydroceles), but only a professional evaluation can determine the cause.

Male Infertility

A male factor contributes to infertility in 40-60% of couples (male factor alone accounts for 20-30%, combined male and female factors for another 20-30%). Unexplained infertility accounts for 10-20% of cases.

Causes

Idiopathic infertility (no identifiable cause) accounts for 30-40%. Varicocele — dilated scrotal veins that increase testicular temperature and cause oxidative stress — is responsible for 35-40% of cases. Hormonal causes (hypogonadotropic hypogonadism, Kallmann syndrome, pituitary tumor, anabolic steroid use) account for 2-5%. Post-testicular obstruction (congenital absence of the vas deferens from CF mutations, prior vasectomy, or infection) accounts for 10-20%. Testicular failure (Klinefelter syndrome, cryptorchidism, mumps orchitis, chemotherapy, radiation) accounts for 10-15%. Genetic causes (Klinefelter, Y-microdeletion, CFTR mutations) affect 5-10%. Ejaculatory dysfunction (retrograde ejaculation from surgery, diabetes, or spinal cord injury) accounts for 2-5%.

⚠ Clinical Correlation

Semen analysis is the cornerstone of male infertility evaluation. Normal parameters per WHO 2010: volume 1.5 mL or greater, pH 7.2-8.0, sperm concentration 15 million/mL or greater, total sperm count 39 million per ejaculate or greater, total motility 40% or greater, progressive motility 32% or greater, normal morphology (strict Kruger criteria) 4% or greater, vitality 58% or greater, leukocytes under 1.0 million/mL, and fructose present (indicating normal seminal vesicle function). Two to three samples over several weeks are recommended for confirmation, as there is significant day-to-day variability.

Evaluation

History and physical examination are the first steps, assessing sexual history, prior fertility, medical and surgical history, lifestyle factors, varicocele, testicular atrophy, and secondary sexual characteristics. Semen analysis is performed at least twice. Hormonal evaluation (FSH, LH, total/free testosterone, prolactin, estradiol) is indicated for abnormal semen analysis. Post-ejaculate urinalysis detects retrograde ejaculation. Scrotal ultrasound confirms varicocele, hydrocele, or testicular mass. Genetic testing (karyotype, Y-microdeletion, CFTR mutation) is indicated for azoospermia or severe oligospermia.

Treatment

Varicocoelectomy (microsurgical) improves semen parameters in 60-80% of men. Hypogonadotropic hypogonadism is treated with hCG plus FSH (gonadotropin therapy), stimulating sperm production over 6-18 months. Obstruction is treated with vasovasostomy (post-vasectomy) or transurethral resection of ejaculatory ducts. Idiopathic infertility is managed with lifestyle modification, antioxidants (vitamin C, E, CoQ10, zinc, selenium) with limited evidence, and assisted reproduction (IUI or ICSI-IVF). Severe male factor requires ICSI-IVF. Azoospermia can be treated with testicular sperm extraction (TESE or micro-TESE) plus ICSI.

Vasectomy

Vasectomy is a permanent contraceptive procedure performed under local anesthesia. The vas deferens is isolated, divided, and occluded (ligation, cautery, fascial interposition, or clips). The no-scalpel technique uses a 2-4 mm puncture instead of a 1-2 cm incision, reducing bleeding and hematoma risk. The procedure takes 15-30 minutes. Recovery takes 1-2 days with scrotal support, ice, and limited activity.

It takes approximately 3 months or 20 ejaculations to achieve azoospermia. Confirmation requires one or two negative semen analyses. Efficacy exceeds 99.9%, with a failure rate of 1 in 2,000-4,000 (recanalization is the most common cause of failure).

Side Effects and Complications

Hematoma occurs in 1-5%, managed with scrotal support, ice, and NSAIDs. Infection in 1-3% requires oral antibiotics. Sperm granuloma (inflammatory reaction to leaked sperm) occurs in 10-30% — often asymptomatic and resolves spontaneously. Chronic testicular pain (congestive epididymitis) affects 1-2% significantly. Regret occurs in 2-6% of men, leading to consideration of reversal.

⚠ Caution

A man is not sterile immediately after vasectomy. Sperm remain in the distal vas deferens and seminal vesicles. Another form of contraception must be used until a semen analysis confirms azoospermia. Pregnancy has occurred when couples assumed sterility before confirmation. The post-vasectomy semen analysis is a critical step that should not be skipped. Most surgeons require one negative sample at 3 months (or after 20 ejaculations), and some require two.

Vasectomy Reversal (Vasovasostomy)

Microsurgical reconnection of the vas deferens under general or regional anesthesia takes 2-5 hours. Patency (sperm return) is 30-90% and pregnancy rates are 30-80%, depending on the time since vasectomy. Reversal within 3 years achieves 90% patency and 60-80% pregnancy. After 15 years, patency drops to 30-50%. The alternative is sperm retrieval plus ICSI-IVF.

Circumcision

Circumcision is the surgical removal of the foreskin (prepuce) covering the glans penis. It is performed on 60-65% of male newborns in the United States, with higher rates in the US and Middle East and lower rates in Europe and Asia. The procedure for newborns uses local anesthesia (dorsal penile block or ring block) and a Gomco clamp, Plastibell, or Mogen clamp. Healing takes 5-10 days with petroleum jelly for the first few days.

Benefits and Risks

Benefits include a 10-fold reduction in urinary tract infections in infancy (1% vs 0.1%), virtual elimination of penile cancer, 50-60% reduction in female-to-male HIV transmission (based on African RCTs), 30-50% reduction in HPV and HSV-2 transmission, and elimination of phimosis and paraphimosis. Risks include bleeding (0.1-1%), infection (0.1-0.5%), removal of healthy tissue, anesthetic complications (rare), and meatal stenosis (5-10% of circumcised males). The American Academy of Pediatrics (2012) states that health benefits outweigh risks but does not recommend universal circumcision — parents should make an informed decision based on medical benefits, risks, and cultural, religious, and personal preferences.

Phimosis and Paraphimosis

Phimosis is the inability to retract the foreskin over the glans. It is normal in children (physiologic) and resolves by age 3-5 in 90%. Pathologic phimosis from scarring (balanitis xerotica obliterans, lichen sclerosus) is treated with topical steroid (betamethasone 0.05% twice daily for 4-8 weeks, 70-80% success) or circumcision if that fails. Paraphimosis occurs when a retracted foreskin cannot be returned to normal position, causing a painful, swollen glans that can progress to ischemia. This is an emergency. Manual reduction (compressing the glans and pushing proximally) is the first step. If unsuccessful, osmotic reduction (wrapped in sugar-soaked gauze) or a dorsal slit procedure may be needed.

Penile Anatomy Conditions

Peyronie disease involves a fibrous plaque in the tunica albuginea causing penile curvature with erection. Mild cases may resolve over 1 year. Collagenase (Xiaflex) injection treats curvature of 30-90 degrees. Surgical plication or grafting is reserved for severe or refractory cases. Penile fracture — rupture of the tunica albuginea during erection with a “cracking” sound, sudden detumescence, and swelling — is a surgical emergency requiring immediate repair. Urethral stricture (narrowing from scar tissue) is treated with dilation, internal urethrotomy, or urethroplasty. Hypospadias (urethral opening on the ventral penile surface) is repaired surgically, optimally at 6-18 months of age. Testicular torsion (twisting of the spermatic cord causing testicular ischemia) is a surgical emergency requiring detorsion and orchiopexy within 4-6 hours.

Summary

Regular testicular self-examination detects testicular cancer early when it is highly curable. Male infertility evaluation starts with history, physical exam, and semen analysis, with treatment directed at the underlying cause (varicocele repair, hormonal therapy, or assisted reproduction). Vasectomy is a highly effective permanent contraceptive that requires confirmation of azoospermia. Circumcision reduces certain infection risks, and the decision is personal. Phimosis, paraphimosis, Peyronie disease, and testicular torsion require prompt urologic evaluation.