[Congenital adrenal hyperplasia and testicular hypertrophy]

The role of imaging in congenital adrenal hyperplasia

Congenital adrenal hyperplasia (CAH) is an autossomic recessive disorder caused by impaired steroidogenesis. Patients with CAH may present adrenal insufficiency with or without salt-wasting, as well as various degrees of virilization and fertility impairment, carrying a high incidence of testicular adrenal rest tumors and increased incidence of adrenal tumors. The diagnosis of CAH is made based on the adrenocortical profile hormonal evaluation and genotyping, in selected cases. Follow-up is mainly based on hormonal and clinical evaluation. Utility of imaging in this clinical setting may be helpful for the diagnosis, management, and follow-up of the patients, although recommendations according to most guidelines are weak when present. Thus, the authors aimed to conduct a narrative synthesis of how imaging can help in the management of patients with CAH, especially focused on genitography, ultrasonography, computed tomography, and magnetic resonance imaging.

Adrenal rest tissue in gonads of patients with classical congenital adrenal hyperplasia: multicenter study of 45 French male patients

OBJECTIVES

Several cases of testicular adrenal rest tumours have been reported in men with congenital adrenal hyperplasia (CAH) due to the classical form of 21-hydroxylase deficiency but the prevalence has not been established. The aims of this report were to evaluate the frequency of testicular adrenal rest tissue in this population in a retrospective multicentre study involving eight endocrinology centres, and to determine whether treatment or genetic background had an impact on the occurrence of adrenal rest tissue.

MATERIAL AND METHODS

Testicular adrenal rest tissue (TART) was sought clinically and with ultrasound examination in forty-five males with CAH due to the classical form of 21-hydroxylase deficiency. When the diagnosis of testicular adrenal rest tumours was sought, good observance of treatment was judged on biological concentrations of 17-hydroxyprogesterone (17OHP), delta4-androstenedione, active renin and testosterone. The results of affected and non-affected subjects were compared.

RESULTS

TART was detected in none of the 18 subjects aged 1 to 15years but was detected in 14 of the 27 subjects aged more than 15years. Five patients with an abnormal echography result had no clinical signs. Therapeutic control evaluated at diagnosis of TART seemed less effective when diagnosis was made in patients with adrenal rest tissue compared to TART-free subjects. Various genotypes were observed in patients with or without TART.

CONCLUSION

Due to the high prevalence of TART in classical CAH and the delayed clinical diagnosis, testicular ultrasonography must be performed before puberty and thereafter regularly during adulthood even if the clinical examination is normal.

Testicular adrenal rest tumours in postpubertal males with congenital adrenal hyperplasia: sonographic and MR features

The purpose of this study was to investigate the prevalence of testicular adrenal rest tumours in patients with congenital adrenal hyperplasia (CAH), and to describe sonographic and MR features of these lesions. Seventeen postpubertal male CAH patients underwent scrotal sonography, with colour Doppler, and in 16 of them pre- and postcontrast enhanced T1- and T2-weighted MR images of the testes were obtained. Ultrasound revealed lesions in 16 of 17 patients (94%), bilateral in 10 patients and unilateral in 6 patients. The lesions were typically located adjacent to the mediastinum testis. The maximal diameter of the lesions varied from 2 to 40 mm. Margins were blurred in 11 of 31 lesions. Seventeen of the 20 lesions smaller than 2 cm in diameter were hypoechoic, whereas all 11 lesions larger than 2 cm showed hyperechoic reflections. On MR all lesions were isointense on T1- and hypointense on T2-weighted images and lesion margins were clearly defined. Enhancement of the lesions after intravenous contrast was seen in 13 of 15 patients. In our series the prevalence of testicular adrenal rest tumours in postpubertal CAH patients is much higher than in other reported studies. The lesions may develop from some small, hypoechoic, and multifocal nodules and coalesce to large hypoechoic lesions with hyperechoic reflections on ultrasound. As our results suggest that ultrasonography and MR show the lesions equally well, ultrasonography should be the method of first choice for detection and follow-up of these lesions, because it is the cheapest and quickest imaging technique. In case of a partial orchiectomy, MR is recommended because it shows lesion margins optimally.

Congenital adrenal hyperplasia due to 21-hydroxylase deficiency

More than 90% of cases of congenital adrenal hyperplasia (CAH, the inherited inability to synthesize cortisol) are caused by 21-hydroxylase deficiency. Females with severe, classic 21-hydroxylase deficiency are exposed to excess androgens prenatally and are born with virilized external genitalia. Most patients cannot synthesize sufficient aldosterone to maintain sodium balance and may develop potentially fatal "salt wasting" crises if not treated. The disease is caused by mutations in the CYP21 gene encoding the steroid 21-hydroxylase enzyme. More than 90% of these mutations result from intergenic recombinations between CYP21 and the closely linked CYP21P pseudogene. Approximately 20% are gene deletions due to unequal crossing over during meiosis, whereas the remainder are gene conversions--transfers to CYP21 of deleterious mutations normally present in CYP21P. The degree to which each mutation compromises enzymatic activity is strongly correlated with the clinical severity of the disease in patients carrying it. Prenatal diagnosis by direct mutation detection permits prenatal treatment of affected females to minimize genital virilization. Neonatal screening by hormonal methods identifies affected children before salt wasting crises develop, reducing mortality from this condition. Glucocorticoid and mineralocorticoid replacement are the mainstays of treatment, but more rational dosing and additional therapies are being developed.