Malignant Small Round Blue Cell Tumor of the Kidney Without EWSR1 Rearrangement: Report of a Case and Review of the Literature

Clinical Practice Points center dot Primitive neuroectodermal tumors (PNET) of the kidney are among the Ewing family of tumors, which are associated with rearrangement of the EWSR1 gene on chromosome 22. Certain malignant small round blue cell tumors of soft tissue resemble PNET morphologically but lack the EWSR1 rearrangement. center dot No standard systemic therapy exists for PNET of the kidney. Combinations, including cyclophosphamide, actinomycin, vincristine, doxorubicin, ifosfamide, and etoposide, have been reported to be effective in advanced disease. center dot We report the case of a young woman with a malignant small round blue cell tumor of the kidney that was morphologically similar to PNET without EWSR1 rear-rangement. She received adjuvant chemotherapy with a novel regimen of ifosfamide and doxorubicin alternating with etoposide and cisplatin. She was alive and disease free 5 years later. center dot Recurrence of PNET/round blue cell tumors of the kidney after tumor debulking is not uncommon and is often fatal. This case provides further evidence supporting the strategy of adjuvant chemotherapy for patients with these rare and aggressive kidney tumors. center dot Until further evidence is available, clinicians should consider the adjuvant intervention that we have described for adults with small round blue cell tumors of the kidney, particularly when EWSR1 rearrangement is absent. (C) 2012 Elsevier Inc. All rights reserved.