BackgroundTesticular adrenal rest tumors are a benign condition characterized by the presence of remnants of adrenal tissue within the testes that can lead to infertility. Testicular microlithiasis are calculus deposits within the seminiferous tubules. Both are described in congenital adrenal hyperplasia.ObjectivesDescribe the frequency of testicular adrenal rest tumors and testicular microlithiasis in a Brazilian case series of patients with classic congenital adrenal hyperplasia and to also relate these changes to disease control and hypothalamic-pituitary-gonadal axis disorders.MethodsCase series study. An ultrasound examination of the scrotum was performed on 12 patients between the ages of 5.33 to 22 (14.72 ± 5.26) years. Testicular adrenal rest tumors were classified according to the degree of testicular infiltration in stages by adapting the Grinten’s classification, ranging from the absence of testicular adrenal rests visible by ultrasound (stage ≤ 1) to chronic obstruction of the testicular parenchyma with irreversible damage of the testicle (stage 5).ResultsSix patients (5 salt wasting and 1 simple virilizing) with an average age of 17.27 ± 3.09 years and have gone through puberty showed testicular adrenal rest tumors (Grinten stage ≥ 3). In 2 of the patients there was a coincidence with testicular microlithiasis. The frequency of testicular adrenal rest tumors did not relate with the levels of serum 17-hydroxyprogesterone and androstenedione. In 3 patients with testicular adrenal rest tumors, gonadotropin levels were suggestive of hypergonadotropic hypogonadism and one of hypogonadotropic hypogonadism.ConclusionsTesticular adrenal rest tumors were found in greater frequency during puberty and was not related to hormonal control in this group. Some of them happened with testicular microlithiasis.