Mitotane-Induced Endocrine Alterations in Children with Adrenocortical Carcinoma: Clinical Implications from a 20-Year Retrospective Study

Background/Objectives: Mitotane is a key component in the treatment of adrenocortical carcinoma (ACC), but its endocrine side effects in children remain under-characterized. Methods: We conducted a retrospective analysis of 11 pediatric patients (6 males, 5 females) diagnosed with ACC and followed between 2000 and 2025. Seven received mitotane therapy. Data included age at diagnosis, treatment duration and dosage, serum mitotane levels, and endocrine complications. Results: The mean age at diagnosis was 6.6 ± 1.45 years, with a mean follow-up of 10.05 ± 2.45 years. Patients received mitotane for an average of 2.5 ± 0.54 years, with a mean daily dose of 2805.5 ± 145.82 mg and a mean serum level of 16.1 ± 5.92 mg/mL. All mitotane-treated patients developed adrenal insufficiency, requiring supraphysiological hydrocortisone replacement. Four also required mineralocorticoid therapy. Five developed precocious puberty; two males presented with prepubertal gynecomastia; three females were managed with GnRH analogs or aromatase inhibitors followed by estrogen receptor antagonists. Four patients developed central hypothyroidism, treated with levothyroxine. A positive correlation was found between mean serum mitotane levels and the onset of precocious puberty (p = 0.04), while mitotane levels correlated negatively with the development of central hypothyroidism (p = 0.001). Conclusions: Mitotane therapy in pediatric ACC is strongly associated with significant endocrine dysfunction. These findings emphasize the need for proactive, multidisciplinary endocrine management throughout treatment.