In a 30‑year‑old male, does scrotal sagging indicate testicular atrophy?

Scrotal Sagging at Age 30: Does It Indicate Testicular Atrophy?

Scrotal sagging alone does not indicate testicular atrophy; true testicular atrophy is defined by testicular volume below 12 mL and is associated with impaired spermatogenesis, elevated FSH, or specific risk factors such as cryptorchidism—not by the appearance of the scrotal skin. 1

Understanding Normal Scrotal Anatomy vs. Pathological Atrophy

What Scrotal Sagging Actually Represents

• Scrotal skin laxity increases naturally with age due to loss of elasticity in the dartos muscle and cremasteric tone, and this is a normal aging process that does not correlate with testicular volume or function. 1
• The scrotum's appearance is influenced by ambient temperature, physical activity, and body habitus—factors unrelated to testicular health. 1
• Reactive hydrocele or scrotal wall thickening from inflammatory conditions can alter scrotal appearance and may coexist with testicular pathology, but these are distinct clinical entities requiring ultrasound evaluation. 2

Defining True Testicular Atrophy

• Testicular volumes below 12 mL are definitively considered atrophic and warrant clinical investigation, particularly when associated with elevated FSH (>7.6 IU/L), history of cryptorchidism, or infertility. 1
• Normal adult testicular volume ranges from 15–18 mL, corresponding to a testicular length of approximately 4 cm. 1
• A size discrepancy between testes greater than 2 mL or 20% warrants scrotal ultrasound to exclude structural pathology, regardless of absolute volume. 1

When to Investigate for Testicular Atrophy

High-Risk Clinical Scenarios Requiring Workup

Age under 30–40 years with testicular volume <12 mL carries a ≥34% risk of intratubular germ cell neoplasia (TIN) in the contralateral testis if testicular cancer develops. 1 If untreated, invasive testicular tumor develops in 70% of TIN-positive testes within 7 years. 3, 1

Red-Flag History Elements

• History of cryptorchidism (undescended testes) is the single most important risk factor, substantially increasing both atrophy and testicular cancer risk. 3, 1
• Infertility concerns or abnormal semen parameters (concentration <20 million/mL, motility <50%, or abnormal morphology) correlate strongly with reduced testicular volume. 3, 1
• Use of anabolic steroids, exogenous testosterone, or chronic opioids causes reversible testicular atrophy through hypothalamic-pituitary-gonadal axis suppression. 1, 2
• Prior chemotherapy, pelvic radiation, or inguinal hernia repair are recognized causes of testicular atrophy. 4, 5, 6
• Systemic diseases including diabetes, chronic liver disease, chronic kidney disease, or HIV infection are associated with secondary hypogonadism and testicular shrinkage. 1

Physical Examination Priorities

• Measure testicular volume using a Prader orchidometer, which provides a reliable surrogate for ultrasound measurement and is cost-effective in clinical practice. 1
• Palpate for varicoceles, which are the most common reversible cause of male infertility and can cause ipsilateral testicular atrophy. 7
• Assess testicular consistency and symmetry; firm or hard areas raise concern for malignancy, while bilateral soft small testes suggest primary testicular failure. 3, 1
• Examine for epididymal abnormalities, vas deferens patency, and scrotal wall thickening to distinguish inflammatory from atrophic processes. 3, 2

Diagnostic Algorithm for Suspected Testicular Atrophy

Step 1: Hormonal Evaluation

• Obtain morning serum FSH, LH, and total testosterone (drawn between 08:00–10:00 h) on two separate occasions to establish reliable baseline values. 1
• Elevated FSH (>7.6 IU/L) with testicular volume at or below 12 mL indicates reduced testicular reserve and impaired spermatogenic capacity. 1, 2
• The LH pattern distinguishes primary from secondary hypogonadism: elevated LH suggests primary testicular failure, while low or normal LH points toward hypothalamic-pituitary dysfunction. 1
• Measure serum prolactin if LH is low or low-normal to exclude hyperprolactinemia from pituitary adenoma or medications. 1

Step 2: Semen Analysis (If Fertility Is a Concern)

• Perform semen analysis if testicular volume is borderline (12–15 mL) or if infertility is suspected, as volume alone does not reliably predict fertility. 3, 1
• Obtain at least two semen analyses separated by 2–3 months to account for natural variability. 2
• Reference ranges include: ejaculate volume 1.5–5.0 mL, sperm concentration >20 million/mL, motility >50%, and normal morphology per WHO or Kruger criteria. 3

Step 3: Scrotal Ultrasound

• Request scrotal ultrasound with Doppler when physical examination is difficult (large hydrocele, inguinal testis, epididymal enlargement, thickened scrotal skin) or when testicular volume is <12 mL to confirm atrophy and exclude masses. 1, 2
• Use the Lambert formula (Length × Width × Height × 0.71) for accurate testicular volume calculation; the traditional ellipsoid formula (0.52 coefficient) systematically underestimates volume by 20–30%. 1
• High-frequency probes (>10 MHz) maximize resolution and accurate caliper placement. 1

Step 4: Genetic Testing (If Severe Oligospermia or Azoospermia)

• Karyotype analysis is strongly recommended when FSH is elevated and testicular volume is <12 mL to screen for Klinefelter syndrome (47,XXY), the most common genetic cause of primary testicular failure. 1, 2
• Y-chromosome microdeletion testing should be offered if sperm concentration is <5 million/mL or azoospermia is present, as chromosomal abnormalities occur in 10% of these patients. 1, 2

Management Based on Findings

If Testicular Volume Is Normal (≥15 mL) and Hormones Are Normal

• Reassure the patient that scrotal sagging is a normal anatomical variant unrelated to testicular function or fertility. 1
• No further workup is indicated unless symptoms develop or fertility concerns arise. 1

If Testicular Volume Is Borderline (12–15 mL)

• Obtain hormonal evaluation (FSH, LH, testosterone) and semen analysis to assess testicular reserve. 1
• Repeat semen analysis every 6–12 months if parameters are borderline to detect early decline. 1
• Teach testicular self-examination given the increased cancer risk with smaller volumes. 1

If Testicular Volume Is <12 mL (Definitive Atrophy)

• Refer to urology if age <30 years, history of cryptorchidism, or presence of testicular mass due to ≥34% risk of TIN. 3, 1
• Discuss sperm banking immediately if any sperm are present in ejaculate, preferably 2–3 separate collections with 2–3 days abstinence between collections. 2
• Never initiate testosterone replacement without first clarifying fertility intentions, as exogenous testosterone causes complete azoospermia that may take months to years to recover. 1, 2
• If secondary hypogonadism is confirmed (low LH/FSH with low testosterone), consider human chorionic gonadotropin (hCG) injections as first-line treatment to restore testosterone production and spermatogenesis. 2

Common Pitfalls to Avoid

• Do not confuse scrotal skin laxity with testicular atrophy; only objective measurement of testicular volume (by orchidometer or ultrasound) defines atrophy. 1
• Do not rely on a single semen analysis, as natural variability can be misleading; obtain at least two analyses separated by 2–3 months. 2
• Do not treat subclinical varicoceles found on ultrasound; only palpable varicoceles improve fertility outcomes after repair. 2
• Do not use the traditional ellipsoid formula (0.52 coefficient) for testicular volume calculation, as it systematically underestimates volume and may lead to inappropriate classification of atrophy. 1
• Do not start testosterone replacement in men with borderline testicular volume without first obtaining semen analysis and discussing fertility preservation, as exogenous testosterone will completely suppress remaining spermatogenesis. 1, 2