Syndrome of ectopic ACTH secretion in a patient without a verified tumor

Рrevalence of endogenous hypercortisilism is about 5–6 cases per 1 million people. ACTH-dependent hypercortico- sis in the general structure is about 80%. Among this cohort of patients in 70–75% the cause of hypersecretion of ACTH is corticotrophinoma, about 10% are diagnosed with hyperplasia of corticotrophs, in the remaining 15–20% – neuroendocrine tumors of different locations, producing ACTH and / or corticoliberin. With ectopic ACTH syndrome the development of clinical manifestations is faster than with corticotropinoma, which determines the nature of the clinical picture. Difficulties in identifying the primary focus hypersecretion of ACTH may be due to its small size, absence or nonspecificity of the clinical picture from the primary focus, early metastasis in the case of malignant tumors. Besides, clinical manifestations of hyper- cortisolism can be considered and as independent nosological units, which creates certain difficulties at the stages of early diagnosis and timely treatment of ectopic ACTH syndrome.