BACKGROUND 21-hydroxylase deficiency, an essential enzyme for glucocorticoid and mineralocorticoid synthesis, is the cause of congenital adrenal hyperplasia (CAH) in more than 95% of cases. It is an autosomal recessive disorder encoded by the CYP21A2 gene, categorized into classical forms, which encompass the salt-wasting (SW) and simple virilizing (SV) forms, as well as the nonclassical form (NC). The aim of medical treatment is to replace missing glucocorticoids and, if necessary, mineralocorticoids, while also reducing elevated adrenal androgens. CASE REPORT We present the case of a 42-year-old woman with CAH who discontinued therapy during adolescence and was admitted to hospital with fatigue, nausea, and severe abdominal pain. A CT scan showed an extreme enlargement of the adrenal glands. Laboratory tests revealed elevated levels of 17-hydroxyprogesterone and other adrenal androgens, along with normal plasma metanephrine levels. Decreased morning cortisol levels suggested partial adrenal insufficiency requiring glucocorticoid replacement therapy. Due to the development of several serious complications and clinical deterioration, the multidisciplinary team recommended bilateral removal of masses measuring 300×250×200 mm on the right side and 250×200×200 mm on the left side. Histological and immunochemical examination confirmed the presence of giant myelolipomas with adrenal cortex hyperplasia. CONCLUSIONS Adrenal tumors, particularly myelolipomas, have a higher prevalence in patients with CAH. Our case report provides further evidence of the suspected link between non-compliant CAH therapy and the development of myelolipomas, along with promotion of their pronounced growth.