Malignant peripheral nerve sheath tumor of kidney-A case report.

Background: Malignant peripheral nerve sheath tumors (MPNSTs) are very rare soft-tissue tumors. These tumors originate from Schwann cells or pluripotent perineural cells of the neural crest. An isolated MPNST of the kidney is extremely rare and has been reported in only six cases to date.

Methods: A 30-year-old female with an unremarkable past medical and surgical history presented with an enlarging, right-sided abdominal mass for the last 3 months. A CT scan of the abdomen and pelvis showed a large exophytic mass arising from the right kidney. A metastatic work-up was negative, so a right radical nephrectomy was performed. Histopathological and immunohistochemical studies confirmed the diagnosis of an MPNST.

Conclusions: MPNSTs are rare and aggressive soft-tissue sarcomas that are usually associated with neurofibromatosis type 1 (NF-1) but that also occur post-radiation and sporadically. These tumors are highly malignant neoplasms with a high recurrence rate and distant metastases. Complete surgical excision remains the mainstay of treatment due to the limited response of MPNSTs to both chemotherapy and radiotherapy. Conclusions: MPNSTs arising from the kidney are very rare. Complete surgical resection provides the only hope for cure. Postoperative chemotherapy and radiotherapy are still controversial, although postoperative radiotherapy is currently recommended by an oncology consensus group.