RESUMEN
Summary: Cushing's syndrome due to ectopic adrenocorticotropic hormone (ACTH) secretion (EAS) by a pheochromocytoma is a challenging condition. A woman with hypertension and an anamnestic report of a 'non-secreting' left adrenal mass developed uncontrolled blood pressure (BP), hyperglycaemia and severe hypokalaemia. ACTH-dependent severe hypercortisolism was ascertained in the absence of Cushingoid features, and a psycho-organic syndrome developed. Brain imaging revealed a splenial lesion of the corpus callosum and a pituitary microadenoma. The adrenal mass displayed high uptake on both 18F-FDG PET/CT and 68Ga-DOTATOC PET/CT; urinary metanephrine levels were greatly increased. The combination of antihypertensive drugs, high-dose potassium infusion, insulin and steroidogenesis inhibitor normalized BP, metabolic parameters and cortisol levels; laparoscopic left adrenalectomy under intravenous hydrocortisone infusion was performed. On combined histology and immunohistochemistry, an ACTH-secreting pheochromocytoma was diagnosed. The patient's clinical condition improved and remission of both hypercortisolism and catecholamine hypersecretion ensued. Brain magnetic resonance imaging showed a reduction of the splenial lesion. Off-therapy BP and metabolic parameters remained normal. The patient was discharged on cortisone replacement therapy for post-surgical hypocortisolism. EAS due to pheochromocytoma displays multifaceted clinical features and requires prompt diagnosis and multidisciplinary management in order to overcome the related severe clinical derangements. Learning points: A small but significant number of cases of adrenocorticotropic hormone (ACTH)-dependent Cushing's syndrome are caused by ectopic ACTH secretion by neuroendocrine tumours, which is usually associated with severe hypercortisolism causing severe clinical and metabolic derangements. Ectopic ACTH secretion by a pheochromocytoma is exceedingly rare but can be life-threatening, owing to the simultaneous excess of both cortisol and catecholamines. The combination of biochemical and hormonal testing and imaging procedures is mandatory for the diagnosis of ectopic ACTH secretion, and in the presence of an adrenal mass, the possibility of an ACTH-secreting pheochromocytoma should be taken into account. Immediate-acting steroidogenesis inhibitors are required for the treatment of hypercortisolism, and catecholamine excess should also be appropriately managed before surgical removal of the tumour. A multidisciplinary approach is required for the treatment of this challenging entity.
RESUMEN
Extraventricular neurocytoma (EVN) is an exceedingly rare brain tumor. The radiologic and histologic features of EVN are insidious, and only a few reports and clinical cases describe the characteristics of the tumor, which may show different presentations. We report a case of atypical EVN in a 23-year-old man; Computed Tomography and Magnetic Resonance Imaging features of the mass are described, and differential diagnosis are illustrated. In light of the high variability of imaging presentation, the definitive diagnosis of EVN remains histologic. Although some cases have already been reported in the literature, we believe that the description of our case could be useful to increase the knowledge of this insidious tumor, which has gained recognition only over the past 2 decades and should be included in the differential diagnosis in young patients who present brain tumors.