CyberKnife radiation therapy for malignant myopericytoma in a pediatric patient: a case report and review of the literature.

BACKGROUND

Malignant myopericytoma is a very rare malignant soft tissue tumor which usually develops during adulthood. It has a very poor prognosis due to its aggressive nature and frequent distant metastases.

METHODS

In our case report, we present a 17-month-old girl with malignant myopericytoma who was successfully treated using CyberKnife (Accuray; Sunnyvale, CA, USA) stereotactic radiotherapy.

RESULTS

A rare localization of the tumor caused significant challenges during the course of treatment. Radical surgical resection was not achievable due to the tumor's location in the inner ear; therefore chemotherapy was initially given to the patient. However, due to the fast progression of the tumor during chemotherapy, we decided to use CyberKnife stereotactic radiosurgery (SRS; 5 fractions of 7 Gy) in order to prevent further invasion of the surrounding tissues. During SRS, tumor growth stopped and the tumor then gradually regressed. Since completion of treatment (currently almost 5 years) our patient has been in complete remission without any significant side effects of the radiation therapy.

CONCLUSION

In our recent experience, systemic chemotherapy combined with CyberKnife SRS proved to be effective in a patient with a rare malignant myopericytoma.