Testicular adrenal rests

Last revised by Arlene Campos on 20 Jun 2024

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

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

  • testicular adrenal rest tumor (TART)

  • testicular adrenal rest tissue

  • testicular tumor of the adrenogenital syndrome

  • testicular adrenal-like tissue

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

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.

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

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. Variable vascularity on color Doppler has been reported, being hypovascular rather than hypervascular 4.

  • T1: iso- or slight hyperintense signal

  • T2: hypointense signal

  • DWI: no diffusion restriction

  • T1 C+ (Gd): avid homogeneous post-contrast enhancement

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

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