RESUMO
Cushing's disease is most commonly caused by a corticotrope adenoma of the pituitary. Between 50 and 70% of patients with spontaneous hypercortisolism have ACTH-producing pituitary adenomas. The tumors are usually microadenomas with approximately 20% of patients with the disease showing no evidence of tumor on CT-scans or MR imaging of their pituitary glands. In contrast to patients with ectopic ACTH production, plasma ACTH concentrations in patients with spontaneous disease are generally within the normal range. We describe here a patient with a pituitary macroadenoma that showed evidence of necrosis on MRI. The patient had an atypical clinical presentation with plasma ACTH levels considerably higher than that seen in patients with non-ectopic ACTH-secretory syndrome, markedly elevated urine free cortisol, lack of phenotypical signs of hypercortisolism such as wide purplish striae, and whose most prominent and distressing symptom was severe myopathy that resulted in the patient becoming bed-ridden. Psychosis was another striking feature in this patient who during his hospital course developed multiple opportunistic infections that contributed to his demise.