ATYPICAL CLINICAL PRESENTATION OF ACTH-DEPENDENT CUSHING'S SYNDROME IN A PATIENT TREATED WITH RETINOIC ACID

Objective: The leading signs and symptoms of Cushing's syndrome (CS) in adolescents, which depend on the duration and the severity of hypercortisolemia, are: a decrease in growth velocity with an increase in body weight, redistribution of fat tissue (round face), and less commonly, acne due to hyperandrogenization. a widely used antiacne drug, retinoic acid, can change the clinical presentation of CS awl delay the diagnosis. Methods: We report an atypical presentation of adrenocorticotropic hormone (ACTII)-dependent CS in a patient treated with retinoic acid due to severe acne. Results: Three months after the discontinuation of retinoic acid treatment (at a dose of 40 mg daily for 6 months, with a 4 month break and then for an additional 6 months), a 17.5-year-old male presented with short stature (-3.0 SD), muscle weakness, difficulty concentrating, insomnia, and depressed mood. Body weight (body mass index, 22 kg /m2), fat tissue distribution, pubertal status (testicular volume equal to 20 mL, pubarche axillarche present), and blood pressure were nonnal, and the patient's bone age was equal to his chronologic age. His bone mineral density was decreased (Z-score, 3.5 SD). The morning serum cortisol level was normal (8:00 AM, 171.9 ng/mL) and did not decrease in the evening (8:00 PM, 178.9 ng/mL) or after 1 mg of dexamethasone (100.4 ng/mL). The patient's urinary free cortisol was elevated on 3 occasions (274.5, 217.3, and 253.7 mu g/day). Increased ACTH levels in the morning (97.5 to 141.1 pg/mL) and postcorticoliberine (577.6 pg/mL) pointed to ACTH-dependent. A magnetic resonance imaging scan of the pituitary gland confirmed the presence of a microadenoma. Conclusion: Retinoic acid treatment may alter the clinical presentation of ACTH-dependent CS and consequently delay the diagnosis.