A Case of Extraskeletal Ewing^|^rsquo;s Sarcoma of the Oral Floor

Extraskeletal Ewing’s sarcoma (EES) is a rare disease that is one of the Ewing’s sarcoma family of tumors (ESFT). Adult cases of ESFT often arise from extraskeletal sites. We herein describe a case of EES originating from the left oral floor. A 37-year-old man had a 3-month history of a painless mass in the left oral floor. The mass had enlarged without adhesion to the mandible. The patient underwent removal of the mass at a previous hospital. The postoperative diagnosis was Ewing’s sarcoma. The surgical margin was histologically positive, and thereafter the patient was admitted to our hospital. Contrast enhanced MRI and PET/CT demonstrated no residual tumor. The patient received a full course of chemotherapy (VDCA-IE therapy) with surgery. We performed oral floor partial excision following four preoperative chemotherapy courses. Histologically there was no residual tumor. The patient received a 13-course chemotherapy regimen after the operation. One year and seven months have passed from initial diagnosis without any signs of either local recurrence or distant metastasis.