Acute Exacerbation of Idiopathic Pulmonary Fibrosis Following Treatment for Cushing's Syndrome

A 64-year-old Japanese man with mild reticular shadows in both lungs developed a lung tumor causing ectopic Cushing's syndrome. He was prescribed an adrenal inhibitor, which controlled his hypercortisolemia. However, he developed acute exacerbation of idiopathic pulmonary fibrosis (IPF) and died within weeks. Previous studies have suggested a dosage reduction of corticosteroids for IPF as a triggering event for acute exacerbation. The present case suggests that IPF coexisting with Cushing's syndrome may have been exacerbated after the correction of hypercortisolemia. Therefore, close monitoring of cortisol levels along with the clinical course of IPF is required in similar cases that require the correction of hypercortisolemia.