[Clinical characteristics of testicular adrenal rest tumor and factors associated with its occurrence in 21-hydroxylase deficiency patients]

Objective: To analyze the occurrence and clinical characteristics of testicular adrenal rest tumor (TART) in 21-hydroxylase deficiency (21-OHD) patients, and further explore the possible factors related to the occurrence of TART. Methods: Twenty-seven male 21-OHD patients who visited Peking Union Medical College Hospital from January to December 2018 were enrolled and their clinical and biochemical data were collected. The CYP21A2 mutations were identified by Sanger sequencing and multiple ligation probe amplification (MLPA). Patients were divided into different subgroups according to the residual activity of 21-hydroxylase: Null (residual enzymatic activity 0, 3 cases), group A (0-<1%, 9 cases), group B (1%-5%, 7 cases), group C (20%-50%, 2 cases) and group D (6 cases). The ultrasound of testis was used to detect whether there was TART and its morphological characteristics. Results: Among 27 patients with 21-OHD [average age (17.4±9.3) years], 55.6% (15/27) had TART lesions, most of them were adolescents, and the youngest was only 4 years old. The lesions were mostly bilateral and hypoechoic. The levels of 17α-hydroxyprogesterone (17-OHP) and progesterone in patients with TART were higher than those in patients without TART [17-OHP: 199.6 (62.1, 232.7) nmol/L vs 7.4 (3.2, 105.0) nmol/L, P=0.003; progesterone: 97.1 (42.0, 126.8) nmol/L vs 5.4 (0.7, 20.0) nmol/L, P=0.004]. There was a correlation between the occurrence of TART and genotype of CYP21A2. Patients with Null and A genotypes were more likely to have TART than those with B and C genotypes (8/12 vs 4/9, P=0.021). Conclusions: TART is common in 21-OHD male patients, which is related to 17-OHP and CYP21A2 genotype. It is of great significance for the early screening of TART in 21-OHD patients.