Does the scrotum become looser or tighter in cases of testicular atrophy?

Scrotal Changes in Testicular Atrophy

In testicular atrophy, the scrotum typically becomes looser and more lax as the testicular volume decreases, with the scrotal skin appearing redundant relative to the reduced testicular size.

Physical Examination Findings

The key physical finding in testicular atrophy is reduced testicular volume below 12 mL, which represents the lower limit of normal testicular size 1, 2, 3. When a testicle atrophies, several changes occur:

• The affected testis becomes smaller and softer in consistency, which can be measured using a Prader orchidometer during physical examination 2, 3
• The scrotal skin becomes relatively loose and redundant as the testicular volume decreases, since the scrotal sac does not proportionally shrink with the testicle 4, 5
• Testicular atrophy is defined as a volume difference greater than 50% compared to the contralateral testis when measured by orchidometer or ultrasound 4

Clinical Assessment Methods

Physical examination should specifically assess:

• Testicular size using a Prader orchidometer, which provides accurate volume measurements and is more practical than ultrasound for routine clinical assessment 2, 3
• Testicular consistency, as atrophied testes typically feel softer than normal 1, 2
• Comparison with the contralateral testis, since a size discrepancy greater than 2 mL or 20% warrants further evaluation 3
• Associated scrotal findings including the presence of hydrocele, varicocele, or epididymal abnormalities 1

Ultrasound Findings in Atrophied Testes

When scrotal ultrasound is performed (indicated when physical examination is difficult or inadequate), atrophied testes demonstrate:

• Reduced testicular volume below 12 mL with accurate volumetric measurements 2, 6
• Non-homogeneous testicular architecture representing impaired spermatogenesis 6
• Decreased blood flow on color Doppler examination with reduced arterial velocity and increased resistive index 6
• Possible testicular microcalcifications, which are associated with increased cancer risk 6

Important Clinical Caveats

The scrotal skin itself does not actively tighten or contract in response to testicular atrophy—rather, it remains relatively unchanged in surface area while the testicular volume decreases, creating the appearance of looseness 4, 5. This is distinct from the normal cremasteric reflex, which causes temporary scrotal tightening in response to cold or stimulation 1.

Testicular atrophy carries significant clinical implications beyond cosmetic concerns:

• Volumes below 12 mL are associated with spermatogenic failure, particularly when FSH levels exceed 7.6 IU/L 2, 6
• Atrophied testes have increased risk of testicular cancer, with men under 30 years having a greater than 34% risk of intratubular germ cell neoplasia 1, 3
• Patients should be taught testicular self-examination for early cancer detection 2, 3
• Contralateral testicular biopsy should be considered in high-risk patients with testicular cancer and contralateral atrophy 1, 3

Timeline of Atrophy Development

When testicular atrophy develops as a complication (such as after testicular torsion or trauma):

• Clinical evidence of atrophy typically appears by 12-14 months after the inciting event 4
• Half of patients undergoing testicular salvage after torsion will develop atrophy even when the testis appeared viable intraoperatively 4
• Scrotal trauma results in testicular atrophy in approximately 50% of cases at follow-up examination 5