Spontaneous Regression of Metastatic Extraskeletal Myxoid Chondrosarcoma.

Spontaneous regression of tumors is very unusual and is defined as a partial or complete disappearance of metastatic tumors without any treatment. This phenomenon has been reported in almost all types of cancer. The patient was a 25-year-old woman who presented with multiple pulmonary nodules on her bilateral lungs on the annual chest roentgenograph. Simultaneously, a swelling mass on her subcutaneous inguinal region was observed. The diagnosis of the inguinal mass was extraskeletal myxoid chondrosarcoma. The inguinal mass and pulmonary nodules spontaneously regressed without any treatment after biopsy. The patient was doing well without evidence of recurrence at 1 year after the operation without any additional therapy. Our case is the first clinical one that indicated a possibility of histologic regression of extraskeletal myxoid chondrosarcoma.