Ectopic ACTH syndrome: Description, Causes and Risk Factors:Abbreviation: EAS.The ectopic ACTH syndrome was ?rst described in 1928 by Brown as a `pluriglandular syndrome of the bearded woman', and subsequently by Leyton who described a patient with thymus cancer and ectopic ACTH secretion. The term `ectopic ACTH syndrome' is considered a misnomer by some authors, since many non-neoplasic tissues produce ACTH. However, the majority of mRNA for proopiomelanocortin (POMC) in peripheral tissues is the 800 nt transcript that lacks the signal sequence encoded in exons 1 and 2, and although translated it is unlikely to cross endoplasmic reticulum for processing. In these tissues, the ACTH produced is truncated and thus has lower biological activity due to the lack of adequate processing of POMC.The EAS occurs in around 5-10% of all cases of ACTH-dependent hypercortisolism. Different from Cushing's disease, which presents a predominance of 75-80% in the female sex, the EAS is only slightly more frequent in women. The mean age of clinical presentation, as shown in several series published in the literature, varies from 45 to 50 years, being higher when compared with the mean age of Cushing's disease, which is 30-40 years.The most common places for an ectopic ACTH-producing tumor are in the lung and thymus, both located in the chest. Other very rare places include the thyroid, ovary, adrenal gland, and liver. Just like a pituitary adenoma, these ACTH-producing tumors make too much ACTH and in turn cause the adrenal glands to make too much cortisol.Symptoms:Irritability.

• Mania.
• Depression.
• Psychosis.
• Diabetes mellitus (<20%).
• Osteoporosis.
• Weakness (proximal muscles) andfatigue.
• Leukocytosis
• Hyperlipidemia.

Diagnosis:Localization of the ACTH-secreting tumor is often difficult and may require multiple modalities, including computed tomography (CT), magnetic resonance imaging (MRI), and octreotide scanning to lessen the likelihood of false-positive results by a single imaging technique.Treatment:Optimal treatment for ectopic ACTH syndrome is dependent on the ability to localize the source of ACTH. Surgical resection of the source may be curative in many cases. In other cases, treatment by bilateral adrenalectomy or steroidogenesis inhibitors may need to be considered as options or to control the hypercortisolemia during the localization process. Patients with ectopic ACTH syndrome caused by occult neuroendocrine tumors have a more favorable prognosis than cases caused by small-cell lung cancer, medullary carcinoma of the thyroid, or gastrinoma.NOTE: The above information is educational purpose. The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition.DISCLAIMER: This information should not substitute for seeking responsible, professional medical care.