Steroid diagnosis of Cushing's syndrome evaluated by pattern recognition.

: Six steroid tests based on urinary free cortisol and plasma total cortisol were used for differentiating between 27 patients with Cushing's syndrome in whom the diagnosis was confirmed by operation or autopsy and 25 obese subjects imitating this syndrome in whom hypercortisolism was excluded by repeated examinations performed over several years. The complex quantified evaluation of these tests by computer pattern recognizing procedure allowed a correct classification of all subjects. The procedure quantitatively ascertained the usefulness of performing steroid tests repeatedly at due intervals for conclusive diagnosis. The response of urinary free cortisol to the low-dose dexamethasone and diurnal rhythm of plasma total cortisol appear to be the most important tests.