Disappearance of Ewing's sarcoma following bacterial infection: a case report.

We report a patient with multiple metastases of Ewing's sarcoma in whom the tumor vanished after a bacterial infection. To the best of our knowledge, no comparable case with Ewing's sarcoma has been reported in the literature. The patient was a 17-year-old male who had an irregular destructive lesion of the left pelvis on radiologic examination. Pathologic examination of a biopsy specimen revealed Ewing's sarcoma. After the operation, a roentgenogram showed multiple spinal metastases with paraplegia. Despite initiation of chemotherapy, a subsequent bone scan showed several areas of increased uptake indicating multiple metastatic lesions. A fistula with purulent discharge opened at the operative site. While being treated with antibiotics and fistula irrigation, the fistula narrowed and his high fever subsided. During this period, radiologic examinations indicated that the multiple bone metastases had nearly disappeared. Nine years after the operation, the patient is alive without any evidence of tumor. We postulate that the antitumor activity in this patient resulted from the bacterial infection, and believe that this case supports continued consideration of immunotherapy for cancer.