When Should Boys With CAH Begin TART Ultrasound Screening?

Testicular adrenal rest tumors (TARTs) are non-cancerous masses that develop inside the testicles of some males with congenital adrenal hyperplasia (CAH) ^[1]. These tumors grow from cells in the testes that are very similar to adrenal gland tissue ^[1]. Screening for TARTs typically begins around puberty—often considered around ages 10 to 12—using an ultrasound, though some high-risk boys may start earlier ^[2]. The goal of screening is to detect these masses early so your care team can monitor them and help protect your son’s long-term fertility.

Important Safety Warning: While TARTs are non-cancerous, any new lump, asymmetry, persistent enlargement, or unexplained testicular pain should be evaluated by a doctor promptly. Do not assume a new lump is a TART; other conditions, including testicular torsion (which causes sudden, severe pain) or testicular cancer, require urgent assessment ^[3].

Why Do TARTs Develop?

In males with CAH, an enzyme defect impairs the body’s ability to produce cortisol. To compensate, the pituitary gland in the brain produces high levels of ACTH (adrenocorticotropic hormone) to stimulate the adrenal glands ^[1].

However, some cells inside the testes also have receptors that respond to ACTH ^[4]. Chronic exposure to high ACTH levels can cause these adrenal-like cells to grow and multiply, forming TARTs ^[5][1]. While poor hormonal control and higher ACTH levels are strongly linked to tumor growth, TARTs can sometimes develop even in boys whose CAH appears well-managed ^[5][6].

Are TARTs Dangerous?

When a diagnosis of TART is confirmed, these masses are benign, meaning they are not cancer and will not spread to other parts of the body ^[1].

However, they do pose a risk to your son’s future fertility. TARTs are often bilateral (occurring in both testicles) and typically grow near the rete testis and seminiferous tubules—the delicate tubes inside the testicle responsible for producing and transporting sperm ^[2]. As the tumors expand, they can physically compress or obstruct these sperm-carrying tubes ^[2].

If left untreated for long periods, large or persistent TARTs can cause potentially irreversible damage, including permanent scarring (fibrosis) and testicular atrophy ^[7][2]. Among adult men with CAH who develop TARTs, studies show higher rates of severe oligospermia (low sperm count) or azoospermia (no sperm in the semen) compared to those without TARTs (e.g., 70% vs 3.6% in one adult cohort) ^[8].

Early detection is key because adjusting glucocorticoids (the steroid medications used to treat CAH) under strict medical supervision can sometimes shrink early-stage tumors and reduce the risk of progression ^[7][9]. However, outcomes vary, and established scarring may not be reversible ^[7].

Do Not Adjust Medications on Your Own: Never increase or change your son’s glucocorticoid doses without the endocrinologist’s supervision. Aggressively trying to suppress ACTH with excessive steroids can cause major side effects, and inadequate doses can lead to an adrenal crisis. Treatment decisions must balance tumor control with steroid-related risks.

Screening Guidelines and Monitoring

Because early-stage TARTs are usually too small to be felt during a physical exam and rarely cause symptoms, imaging is required to find them ^[3][10].

• When to start: Routine screening with a testicular ultrasound is often considered around puberty (ages 10 to 12) ^[2]. However, there is no single universal start age. Some guidelines suggest starting earlier if a boy has signs of early puberty, advanced bone age (when bones mature faster than chronological age), or prolonged periods of poor hormonal control ^[11][12].
• How often to screen: Follow-up intervals vary based on age, symptoms, CAH severity, and local clinic practices. Some centers recommend annual ultrasounds once screening begins, while others adjust the frequency based on clinical need ^[13][14].
• The ultrasound experience: Testicular ultrasound is completely noninvasive and uses no radiation. The clinical team can help ensure the exam is done comfortably, with a parent or chaperone present, respecting your son’s privacy.
• Routine exams: Even when ultrasounds aren’t scheduled, testicular physical exams and puberty assessments are a standard part of routine endocrinology visits.