Secondary adrenal insufficiency in patient with COVID-19 and head and neck cancer

Syndrome of inappropriate antidiuretic hormone (SIADH) secretion is an endocrinological disorder which occurs when there evidence continued (ADH) in the absence appropriate osmotic volume stimulus. Most commonly it caused by different types cancer or medications (eg. diuretics, antidepressants, antipsychotics...). Secondary adrenal insufficiency insufficient adrenocorticotropic (ACTH) and cortisol production. In hypocortisolism, inhibitory mechanism on ADH vanishes causing increased leading to SIADH-like state. Both conditions, SIADH manifest euvolemic hyponatremia, however, its cause can be misdiagnosed result inadequate treatment potentially fatal outcome. Our case about fifty-seven-year-old male patient who was treated with chemoradiotherapy for hematological malignancy oropharynx presented severe hyponatremia se-veral times that almost ended fatally. Considering his malignant disease, diagnosed as a hypona-tremia hypertonic saline fluids fluid intake restriction. However, after having suffered Covid-19 infection given glucocorticoids according protocol at time. The sodium levels finally corrected, secondary has been declared real hyponatremia. often thought patients disease. represents diagnosis exclusion. Before making final diagnosis, thyroid must ruled out. Moreover, imitates results but management potential outcomes these two conditions differ significantly. have previously malignancies options increase risk (chemotherapy, neck skull base radiotherapy, immunotherapy), reserve evaluated. If introduced, glucocorticoid therapy should carefully deescalated because unrecognized insufficiency. This especially applies include protocol, such infection.