Difficulties in differential diagnostics of ACTH-dependent forms of endogenous hypercorticism (literature review and clinical case)

The prevalence of endogenous hypercortisolism (EH) is about 5–6 cases per 1 million people, while the proportion ofACTH-dependent variants is about 80%. Among ACTH-dependent forms of EH, 70–75% of cases are corticotropinomas,15–20% are ACTH-ectopic syndrome. Differential diagnosis of ACTH-dependent forms is the most complex stageof diagnostic search.The article presents a modern algorithm for differential diagnostics of ACTH-dependent hypercorticism. The stagesand sequence of diagnostic tests, their specificity and sensitivity are considered. Particular attention is paid to thefeatures of the clinical picture of the disease, the use of effective laboratory methods that can help the cliniciansuspect the etiology of ACTH-dependent hypercorticism in detection. A description of instrumental research methods,their diagnostic capabilities in terms of visualization of ACTH-secreting tumors is given.The clinical case of a patient with severe EH without a verified tumor demonstrates the complexity of differentialdiagnostics of ACTH-dependent hypercorticism. Difficulties in topical diagnosis may be due to the absence ofpathognomonic signs of the primary lesion and the very small size of the tumor, while the severity of the diseasedoes not always correlate with tumor size. In our case, the severe course of hypercortisolism in the absence of asource of ACTH secretion, despite a thorough diagnostic search, as well as the impossibility of conservative therapydue to the development of acute liver and kidney damage, was the basis for laparoscopic bilateral adrenalectomy.
Keywords: ACTH-dependent hypercortisolism, endogenous hypercortisolism, ACTH-secreting tumor, adrenalectomy,cortisol, Cushing’s disease, topical diagnostics
Conflicts of interest. The authors have no conflicts of interest to declare.
Funding. There was no funding for this study