Testicular adrenal rests in a patient with congenital adrenal hyperplasia: US and MRI features.

We present ultrasonographic and magnetic resonance imaging findings of intratesticular adrenal rests in a 16-year-old patient with congenital adrenal hyperplasia. Scrotal ultrasonography showed bilateral well-delineated homogenous hypoechoic lesions located around the mediastinum testis, which were highly vascularized on power Doppler ultrasonography. Relative to normal testicular parenchyma the lesions were iso- or hyperintense on T1-weighted and hypointense on T2-weighted images. T2-weighted images also showed a target-like appearance caused by a more hypointense peripheral halo around the lesions. The lesions enhanced remarkably on post-contrast images. This case suggests that radiological evaluation of testes, even in the presence of normal physical examination findings, should be included in periodical follow-up of patients with congenital adrenal hyperplasia. Magnetic resonance (MR) imaging is useful in demonstrating the lesions, because the contrast resolution better than with ultrasonography.