Testicular adrenal rests

Testicular adrenal rests are a rare cause of a testicular mass.

Terminology

Testicular adrenal rests can be known by a variety of terms ²:

• testicular adrenal rest tumour (TART)
• testicular adrenal rest tissue
• testicular tumour of the adrenogenital syndrome
• testicular adrenal-like tissue

Epidemiology

Can be found in the testis and surrounding tissues in 7.5-15% of newborns and ~1.5% of adults.

Clinical presentation

Usually, adrenal rests are asymptomatic. If these cells are exposed to elevated levels of adrenocorticotropic hormone, they can enlarge to form masses. They are associated with patients with congenital adrenal hyperplasia and rarely in patients with Cushing syndrome.

Pathology

Aberrant adrenal rests represent collections of cells that have become trapped within the developing gonad during fetal development. The rests are usually less than 5 mm.

Radiographic features 

Ultrasound

As with evaluation of other testicular pathology, ultrasound is the modality of choice.

The sonographic appearance of adrenal rests is variable, with some series describing predominantly hypoechoic masses and others reporting heterogeneously hyperechoic masses with shadowing. Lesions are typically multiple, bilateral, and eccentrically located, usually within the mediastinum testis.

Treatment and prognosis

It is important to suggest this in the differential diagnosis in the appropriate setting as they are benign lesions and unnecessary orchidectomy can be avoided. Appropriate hormone serum bloodwork can help secure the diagnosis.

Treatment with glucocorticoid replacement therapy results in stabilisation or regression of the masses.

Differential diagnoses

• testicular cancer
• testicular abscess
• Leydig cell hyperplasia