Extraskeletal Chondrosarcoma: Long-term Follow-up of a Patient with Metastatic Disease.

Extraskeletal myxoid chondrosarcoma (EMC) is a rare soft tissue sarcoma with an indolent course and poor response to systemic treatment. We present a case of a 53-year-old male who presented with right gluteal extraskeletal myxoid chondrosarcoma. He was treated with wide local excision after receiving 50 Gray of neoadjuvant radiation therapy. Three years later he was found to have a left lower lobe lung nodule that was slowly increasing in size. He underwent a left lower lobectomy and the nodule was confirmed to be consistent with the patient's history of EMC. One year later, lung imaging showed multiple small nodules bilaterally consistent with metastatic disease. The patient opted for watchful waiting approach. Routine follow-up imaging for four years shows a very slow progression of his disease burden. He continues to be asymptomatic. This case demonstrates the natural course of EMC and argues in favor of the watchful waiting approach in treating this disease.