PITFALLS IN THE DIFFERENTIAL-DIAGNOSIS OF CUSHING SYNDROME

Cushing's syndrome is a potentially lethal or invaliding condition wit h a cure rate higher than 80%, if adequate diagnostic and therapeutic procedures are applied. Diagnostic imaging of pituitary and adrenals ( CT, NMR, sonography) discloses only weak evidences of the origin of hy percortisolism, but definite diagnosis is obtained by endocrine testin g in more than 95% of the patients. Test procedures may be confused by a cyclic occurrence of hypercortisolism, the intake of antiepileptics , tuberculostatics or synthetic glucocorticoids and by problems during sample processing for ACTH measurement. Known causes for falsely posi tiv or negative results of standard endocrine tests are described.