FLUCTUATING HYPER-HYPOCORTISOLAEMIA - A VARIANT OF CUSHINGS-SYNDROME

We present a patient with severe Gushing's syndrome secondary to an in vasive pituitary tumour. Cortisol secretion fluctuated between severe hypercortisolaemia associated with features of Gushing's syndrome to r ecurrent symptomatic hypocortisolaemia. Normal ACTH precursors to ACTH ratio during the various stages of cortisol secretion indicated that periodic decreased prohormone processing did not contribute to the uni que presentation in the patient. Thus, the the extreme fluctuations of plasma cortisol levels are most probably due to unexplained erratic c hanges of ACTH secretion.