I have rapid testicular atrophy; what should I do?

Urgent Evaluation for Rapid Testicular Atrophy

You must seek urgent urological evaluation within 1–2 weeks, as rapid testicular size reduction can signal testicular torsion, tumor, or progressive primary testicular failure—all of which require immediate diagnostic workup to prevent irreversible damage or missed malignancy. 1

Immediate Priorities: Rule Out Surgical Emergencies

Testicular Torsion

• Acute testicular torsion presents with sudden-onset scrotal pain, swelling, and a firm, tender testis; surgical exploration within 6–8 hours is essential to prevent testicular loss. 2
• Even if pain is absent or mild, rapid atrophy over days to weeks can follow incomplete or intermittent torsion, making Doppler ultrasound mandatory to assess blood flow. 2, 3
• The Prehn sign (pain relief with testicular elevation) is unreliable for excluding torsion; imaging is required. 2

Testicular Tumor

• A painless solid testicular mass is pathognomonic for testicular cancer, but tumors can present with vague discomfort or swelling mimicking epididymitis. 2
• Scrotal ultrasound with Doppler must be performed urgently to quantify testicular volume, assess architecture, and rule out masses; volumes <12 mL are definitively atrophic. 1, 4
• If a mass is identified, obtain serum tumor markers (β-hCG, AFP, LDH) before any intervention, as these guide staging and prognosis. 2

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Comprehensive Diagnostic Workup

Physical Examination Focus

• Palpate for testicular consistency, masses, and position to exclude torsion, tumor, or acquired cryptorchidism (testicular ascent out of the scrotum). 2, 1
• Examine for varicocele on standing examination; correction of palpable varicoceles can improve semen quality if present. 1
• Document size discrepancy between testes; a difference >2 mL or 20% warrants ultrasound evaluation regardless of absolute volume. 1, 4

Laboratory Evaluation

• Obtain morning serum FSH, LH, and total testosterone (08:00–10:00 h) on two separate occasions to differentiate primary testicular failure (elevated FSH/LH, low testosterone) from secondary hypogonadism (low FSH/LH, low testosterone). 1, 4
• FSH >7.6 IU/L strongly suggests primary testicular dysfunction and non-obstructive azoospermia risk. 1
• Measure serum prolactin to exclude hyperprolactinemia as a cause of secondary hypogonadism. 4
• Perform karyotype analysis if 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. 4, 5

Imaging

• Scrotal ultrasound with Doppler is the gold standard to quantify testicular volume (using the Lambert formula: Length × Width × Height × 0.71), assess blood flow, and detect masses or structural abnormalities. 1, 4
• Testicular volumes <12 mL are definitively atrophic and associated with impaired spermatogenesis, elevated FSH, and increased risk of intratubular germ cell neoplasia (TIN). 1, 4

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Critical History Elements to Elicit

Red-Flag Exposures and Conditions

• Prior undescended testes (cryptorchidism) dramatically raises the risk of atrophy and testicular cancer; men with this history have a 3.6–7.4 times higher risk of germ cell tumors. 4, 5, 6
• Anabolic steroid, exogenous testosterone, or chronic opioid use suppresses the hypothalamic-pituitary-gonadal axis, causing complete azoospermia and testicular atrophy that can persist for months to years after cessation. 4
• Prior chemotherapy or pelvic/testicular radiation causes irreversible testicular shrinkage and impaired spermatogenesis. 4, 5
• History of mumps orchitis, testicular trauma, or torsion can lead to secondary testicular atrophy. 5, 3, 7
• Systemic diseases (type 2 diabetes, chronic liver disease, chronic kidney disease, HIV infection) are associated with functional hypogonadism and reduced testicular volume. 4

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Cancer Risk Stratification

High-Risk Scenarios Requiring Testicular Biopsy

• Age <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. 2, 1, 4
• If TIN is left untreated, approximately 70% progress to invasive testicular cancer within 7 years. 2, 4
• History of cryptorchidism combined with volume <12 mL mandates intensified surveillance and consideration of contralateral testicular biopsy at the time of orchidopexy or if cancer is diagnosed. 2, 4

Surveillance Recommendations

• Teach testicular self-examination given the elevated cancer risk with smaller volumes and cryptorchidism history. 4
• Repeat scrotal ultrasound every 6–12 months if high-risk features are present but biopsy is deferred. 1

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Fertility Assessment and Preservation

Immediate Fertility Evaluation

• Perform semen analysis (×2, separated by 2–3 months) to assess sperm concentration, motility, and morphology; testicular volume <12 mL strongly correlates with impaired spermatogenesis, reduced total sperm count, and decreased sperm concentration. 1, 4
• Testicular volumes of 10–12 mL typically produce oligospermia rather than azoospermia, but progressive decline is possible. 4

Fertility Preservation Options

• Discuss sperm cryopreservation immediately if semen analysis shows declining parameters or if any intervention (surgery, testosterone therapy, chemotherapy) is planned. 1, 4
• Never initiate testosterone replacement without first clarifying fertility intentions, as exogenous testosterone causes complete suppression of spermatogenesis and can result in azoospermia that may take months to years to recover. 1, 4

Monitoring for Progression

• Repeat semen analysis every 6–12 months to detect early decline in sperm parameters, as single analyses can be misleading due to natural variability. 4
• Factors that accelerate decline include chemotherapy/radiotherapy (impairment for up to 2 years), anabolic steroid use, and progressive systemic disease. 4

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Management Algorithm Based on Etiology

If Testicular Torsion is Confirmed

• Immediate surgical exploration and detorsion within 6–8 hours; long-term prognosis for a functional, non-atrophied testis improves the sooner torsion is diagnosed and treated. 2, 3
• Prophylactic contralateral orchiopexy is performed simultaneously to prevent future torsion. 3

If Testicular Tumor is Identified

• Radical inguinal orchiectomy is the primary treatment; any scrotal violation for biopsy must be avoided. 2
• Sperm banking must be discussed before orchiectomy if fertility is desired. 2
• Contralateral testicular biopsy is strongly indicated if testicular volume is <12 mL and age is <30 years, given the 34% TIN risk. 2, 4

If Primary Testicular Failure is Diagnosed

• Treat underlying cause if reversible (e.g., varicocelectomy for palpable varicocele, discontinue testosterone/anabolic steroids, address systemic disease). 1
• Consider microsurgical testicular sperm extraction (micro-TESE) if non-obstructive azoospermia develops and biological paternity is desired; up to 50% of men with elevated FSH still have retrievable sperm. 1
• Testosterone replacement therapy may be initiated for symptomatic hypogonadism only after fertility preservation is complete, as it will suppress spermatogenesis. 1, 4

If Acquired Cryptorchidism is Identified

• Refer to surgical specialist for orchiopexy; acquired cryptorchidism (testicular ascent after documented scrotal position) shares the same adverse histologic features as congenital cryptorchidism. 2
• Testicular biopsy at the time of orchiopexy is recommended to exclude TIN, particularly when testicular volume is <12 mL. 4

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Common Pitfalls to Avoid

• Do not delay imaging with a "trial of antibiotics" if testicular atrophy is documented; epididymitis does not cause rapid testicular shrinkage. 2
• Do not rely on physical examination alone to exclude torsion or tumor; Doppler ultrasound is mandatory. 2
• Do not use the traditional ellipsoid formula (0.52 coefficient) for testicular volume calculation, as it systematically underestimates volume by 20–30%; use the Lambert formula (0.71 coefficient). 4
• Do not start testosterone replacement before completing fertility evaluation and sperm banking, as recovery of spermatogenesis after exogenous testosterone can take years. 1, 4
• Do not dismiss small testicular volume (<12 mL) as "normal variation" in men <40 years with cryptorchidism history; this combination mandates cancer surveillance and fertility assessment. 2, 1, 4