Potential pitfalls in diagnosis of immunotherapy-induced hypothalamic-pituitary-adrenal axis abnormalities: a clinical case.

Short synacthen tests, useful for ruling out adrenalitis and primary adrenal failure, may be normal in early adrenocorticotrophic hormone deficiency and secondary adrenal failure due to residual adrenal reserve.If clinical suspicion of adrenal insufficiency persists despite an initial satisfactory SST, it is important to recognise the need for re-assessment of cortisol levels.Insulin tolerance test remains a useful tool in the investigation of secondary adrenal insufficiency.Levothyroxine replacement may accelerate the metabolism of cortisol in cases of concurrent hypothyroidism and hypoadrenalism, and therefore, glucocorticoid replacement must precede levothyroxine treatment, to avoid adrenal crisis.The prevalence of immunotherapy-related endocrinopathies is likely to increase with increasing use of ICI and it is crucial that clinicians are alert to their subtle symptoms.