Congenital adrenal hyperplasia (CAH) caused by 21-hydroxylase deficiency is an autosomal recessive disease, which leads to cortisol and aldosterone deficiency and hyperandrogenism. Typical medical treatment includes oral glucocorticoid and mineralocorticoid administration to suppress adrenal androgens and to compensate for adrenal steroid deficiencies. However, some patients stopped taking medicine without the doctor's consent. Among these patients, four cases of CAH patients showing the presence of hyponatremia as an initial electrolyte disorder were found with adrenal adenoma. Hypersecretion of adrenocorticotrophic hormone and chronic poor compliance to therapy appears to be associated with the development of the adrenal tumor. Two cases were managed with adrenalectomy because of increasing adrenal tumor size and virilization. Whereas the other two cases did not increase in size and were observed without adrenalectomy. Therefore, it is important that patients with CAH maintain steroid medication to avoid the appearance of adrenal tumor.
Keywords: 21-hydroxylase deficiency; Adrenal tumor; Congenital adrenal hyperplasia; Hyponatremia.