Table 2 Proposed five stage classification of TARTs (modified from [69, 79]).
From: Growth and Reproductive Outcomes in Congenital Adrenal Hyperplasia
| Stage | Histological description | Testicular ultrasound | Reversibility | Treatment options |
|---|---|---|---|---|
| 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. |