Table 2 Proposed five stage classification of TARTs (modified from [69, 79]).

1

Adrenal rest cells within the rete testis

Undetectable by testicular ultrasound

None

2

Proliferation of adrenal rest cells due to growth-promoting factors (such as Angiotensin II and ACTH)

May become visible as one or more small hypoechogenic lesions

Increase dose and intensify glucocorticoid therapy

3

Growth of adrenal rest cells leads to compression of the rete testis, obstruction of the seminiferous tubules, and evidence of gonadal dysfunction ( FSH, LH, sperm, inhibin B)

Detectable

Increase dose and intensify glucocorticoid therapy. Surgery can also be considered.

4

Further hypertrophy and hyperplasia of adrenal rest cells with progressive obstruction of rete testis with fibrosis within the tumor and focal lymphocytic infiltration

Detectable—small tumors may form a single lobulated structure

Consider surgery but may not reverse testicular damage.

5

Chronic obstruction leads to destruction of surrounding testicular parenchyma

Detectable

None—irreversible damage.