Spontaneous remission of unidentified Cushing's disease revealed by hair cortisol analysis.

Pituitary apoplexy is an infrequent but life-threatening complication of pituitary adenomas. When apoplexy occurs in a hormonally active adenoma, this may induce spontaneous remission of the clinical syndrome. In these cases, clinical suspicion of Cushing's disease or acromegaly may arise at presentation, but due to spontaneous remission of active hormone production, it is not possible to biochemically confirm this diagnosis in retrospect. Resolution of clinical symptoms during follow up retrospectively suggests the diagnosis. However, we describe a patient with Cushing's disease presenting with pituitary apoplexy, who was biochemically in remission at presentation. The diagnosis could be confirmed in retrospect using hair cortisol analysis, thereby enabling clinicians to adequately anticipate remission of Cushing's disease.