NEPHROGENIC RESTS IN WILMS-TUMOR PATIENTS WITH THE DRASH SYNDROME

The histological specimens from 12 patients with the Drash syndrome were identified from the National Wilms Tumor Study Group and reviewed for the presence of nephrogenic rests. Of 7 patients with the complete Drash syndrome 6 were evaluable for nephrogenic rests, including 5 (83%) who demonstrated intralobar nephrogenic rests. Of 5 (80%) partial Drash syndrome cases 4 (80%) were also intralobar nephrogenic rest positive. Neither group had perilobar nephrogenic rests identified. In a control population of Wilms tumor patients without the Drash syndrome only 39 of 274 (14%) with unilateral tumor had intralobar nephrogenic rests identified, whereas 26 of 92 (28%) bilateral cases had intralobar nephrogenic rests. There was a significantly higher rate of intralobar nephrogenic rests in complete and partial Drash syndrome cases in the general Wilms tumor population (p < 0.001). Wilms tumor patients with intralobar nephrogenic rests and the Drash syndrome present at a younger age and have a higher rate of bilaterality than rest negative Wilms tumor patients. The strong association of intralobar nephrogenic rests in the Drash syndrome approaches that found in the aniridia complex. However, in other syndromes associated with Wilms tumor, such as the Beckwith-Wiedemann syndrome and hemihypertrophy, there is a high prevalence of perilobar nephrogenic rests. In view of the high incidence of intralobar nephrogenic rests in complete and partial Drash syndrome patients, it is probable that events leading to Wilms tumor in patients with the Drash syndrome occur at an early stage in nephrogenesis.