Cushing's disease cycling over ten years.

Cycles of excessive cortisol secretion have been reported interposed with phases of remission lasting from few days to several months. In this study we report a ten year follow up on a patient who had four episodes of hypercortisolism and Cushing's syndrome associated with hypokalemia and edema and three long lasting spontaneous remissions. This was all caused by corticotroph pituitary adenoma. She demonstrated the longest phase of remission yet recorded in this condition, 4.5 years. The precipitating factors for the recurrence in cyclical Cushing's syndrome are not well defined, but the last recurrence in our patient appeared two months after delivery. We have discussed the continuing uncertainty of the standard dynamic tests in the differential diagnosis of Cushing's syndrome.