Thirteen of 21 patients with stromal-predominant tumors had WT1 mutations and 10 of these were present in the germ line. Twelve mutations are nonsense mutations resulting in truncations at different positions in the WT1 protein and only two are missense mutations. These data show that in a large proportion of a histopathologically distinct subset of WTs the classical two-hit inactivation model, with loss of a functional WT1 protein, is the underlying cause of tumor development. A new radiological technique is described utilising a temporary occlusion balloon inserted via an open venotomy of the left internal jugular vein into the retro- hepatic cava to create a bloodless field to facilitate surgery. Although malignant potential exists in CPDN, all cases reported to date have had a favorable prognosis after surgery alone.
Partial nephrectomy is considered safe, and the treatment of choice in the newborn period.
We report a case of CPDN in a newborn that was successfully treated with partial nephrectomy. More than five years after nephron sparing surgery, the involved kidney shows normal anatomical structure except for a diminished upper pole, no evidence of tumor recurrence and good renal function. Multiple small tumors were present in both kidneys. After 1 month, only a single small lesion was evident, which persisted unchanged. Excisional biopsy 5 months after beginning chemotherapy showed entirely necrotic tumor but apparently unaltered nephrogenic rests.