Cushing's Syndrome Masquerading as Fibromyalgia: A Case Series

Three young female patients with a history of generalized body pain were diagnosed with fibromyalgia. They visited several specialities which related patients' symptoms to their previous diagnosis of fibromyalgia and were treated symptomatically. These patients developed a multitude of clinical features including fractures, hypertension, abnormal weight gain, proximal myopathic pain and bruising. They were seen by rheumatologists whose assessment was that their clinical features were not entirely due to fibromyalgia and suspected that patients have a possible underlying endocrine cause. Patients were referred to an endocrinologist for further tests with suspicion of Cushing's syndrome. Laboratory tests and imaging confirmed a diagnosis of Cushing's syndrome. Two of them had adrenal adenoma and one had iatrogenic corticosteroid use. These cases emphasize the need for thorough clinical evaluation for patients who are thought to have fibromyalgia. Fibromyalgia is a diagnosis of exclusion.