Sonographic features of the testicular adrenal rests tumors in patients with congenital adrenal hyperplasia: a single-center experience and literature review

PURPOSE: Testicular adrenal rests tumor (TART) is a rare kind of benign tumor in the testis. It usually occurred secondary to congenital adrenal hyperplasia (CAH), a hormonal disorder caused by hydroxylase deficiency. As the first-line examination method, ultrasound provides crucial diagnostic information for TART, although misdiagnosis to malignancy is quite common because of its rare prevalence. We aimed to summarize the sonographic manifestations of TART to improve the diagnostic accuracy and specificity. METHODS: Eight CAH patients with TART identified by ultrasound in our medical center were retrospectively reviewed. Clinical and hormonal profile, semen analysis and treatment choices were collected. Sonographic examinations were performed at the first evaluation and interpreted by experienced radiologists individually. All patients received regular follow-up, and 5 patients undertook repeated scrotal ultrasound. A literature review of TART in CAH patients was conducted, with 123 patients from 23 articles since 1990 included. RESULTS: A total of 8 patients aged between 4 to 27 years old were enrolled. 7 of 8 (87.5%) patients exhibited bilateral testicular lesions. The sizes of the testicular lesions were between 0.18 ml to 5.68 ml, and all showed a clear boundary. 10/15 (66.7%) lesions were homogenously hypoechoic, 4/15 (26.7%) were heterogeneously iso-hypoechoic, and 1/15 (6.7%) were homogenously isoechoic. 10/15 (66.7%) lesions were hyper-vascular. The longitudinal follow-up of 5 patients showed testicular lesions changed in terms of size, echogenicity, and vascularity after steroid treatment. A potential correlation may exist between ACTH levels and tumor size (p = 0.066). From the literature review, 100/123 (81%) patients got bilateral lesions, and 95% of them were located near the mediastinum. 80/103 (78%) lesions exhibited a clear boundary, and predominant lesions (74%) were hypoechogenic. Vascularity was with great diversity. Seventy-nine lesions of 44 patients were followed-up by scrotal ultrasound, among which 29 (37%) remained unchanged, 29(37%) shrank, and 21(27%) disappeared. CONCLUSIONS: Key sonographic characteristics of TART are: resembled lesions on both testes, located near the mediastinum, clear boundary, and changed in size or echogenicity after steroid treatment. These features can help radiologists to make an accurate diagnosis of TART.