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 can be clinically identified in 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. They are usually less than 5 mm.

Radiographic features

Ultrasound

As with evaluating 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 orchiectomy 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.