Combined Central Hypothyroidism and Adrenal Insufficiency Associated with Retinoic Acid Therapy for Cutaneous T-Cell Lymphoma

Abstract

Retinoid-induced central hypothyroidism has been previously reported, but there are few reports of retinoid-associated adrenal insufficiency. Here, we present the case of a 72-year-old woman treated with isotretinoin for mycosis fungoides, who subsequently developed both central hypothyroidism and adrenal insufficiency. A 72-year-old woman with a history of mycosis fungoides was treated with isotretinoin 25 mg daily. After five months of therapy, she presented with generalized weakness, dizziness, and unexplained fainting. Thyroid-stimulating hormone (TSH) was 0.29 mIU/L (normal range: 0.4-4.5), free thyroxine (T4) was 6.1 pmol/L (normal range: 8-18), and morning cortisol was 35 nmol/L (normal range: 120-530), suggesting central hypothyroidism and adrenal insufficiency. After discontinuing isotretinoin and initiating hormone replacement therapy, both conditions showed improvement. Retinoid X-receptor (RXR) agonists like isotretinoin have been shown to suppress both TSH and ACTH secretion, leading to hypothyroidism and adrenal insufficiency. This case highlights the importance of monitoring patients on retinoids for endocrine dysfunction. Early recognition and treatment can reverse the effects.