Hypercortisolism in childhood: shortcomings of conventional diagnostic criteria.

Two patients are described in whom hypercortisolism occurred prepubertally as a consequence of bilateral adrenocortical hyperplasia. In contrast with the manifestations of Cushing's syndrome in adults, these children presented with obesity and reduced stature and no other symptoms. Both patients excreted amounts of urinary 17-OHCS before and during a conventional suppression test with dexamethasone (0.5 mg every six hours) which were within the usual normal range. However, when urinary 17-OHCS excretion was expressed per gram of urinary creatinine or per square meter of surface area, and when the dose of dexamethasone was tailored to body mass (20mug/kg/day) the results were clearly abnormal, as were plasma corticoids and (in one patient) cortisol secretion rate. Resumption of linear growth occurred after bilateral adrenalectomy in both patients and was associated, in the one patient so studied, by a return of hypoglycemia-stimulated increases in plasma growth hormone levels from previously suppressed values to the normal range, and by a slight increase in the fasting plasma somatomedin concentration. The observations suggest that pediatric patients with hypercortisolism are likely to be overlooked when conventional criteria for laboratory diagnosis are used, but can be recognized by the simple diagnostic modifications used in these studies.