Multiple retroperitoneal schwannomas mimicking second malignant neoplasms 32 years after Wilms' tumor ablation: Case report

The authors report a case of multiple retroperitoneal schwannomas in a 34-year-old man submitted to left nephrectomy for Wilms' tumor at the age of 2. Preoperative differentiation of the schwannomas from Second Malignant Neoplasms (SMNs) was not possible. The masses were surgically removed: pathologic examination showed typical Antoni A and Antoni B cellular patterns, characteristic of benign schwannomas. Flow cytometric analysis of the DNA ploidy demonstrated both tumors to have a diploid DNA pattern. Two years after the operation, the patient is alive with no evidence of disease and no neurological sequelae. Surgery is advocated for retroperitoneal schwannomas, because it is necessary to differentiate them from other retroperitoneal masses, both benign and malignant; in addition, surgery may provide excellent chances for cure of most retroperitoneal schwannomas, particularly when major nerve roots are not involved.