Combined Extraskeletal Chondrosarcoma of Left Orbit : A Rare Second Primary Tumor of Retinoblastoma Survivor A Case Report

Retinoblastoma, a rare eye malignant tumor of childhood, is generally responsive to chemotherapy or radiation therapy, but the survivors have high risk to development of second primary tumors (SPTs) due to genetic susceptibility and/or prior radiation therapy. The SPTs predominantly occured among heritable form of Retinoblastoma and show worse prognosis than Retinoblastoma itself. A 13 years old girl underwent enucleation to remove tumor mass within her left orbit. This tumor initially appeared 4 years after the patient undergoing right bulbar enucleation and receiving chemotherapy due to Retinoblastoma in her right eye. Clinical and radiologic examination suspected the left one as a late presentation of bilateral Retinoblastoma, but microscopic examination revealed a combined Extraskeletal Chondrosarcoma. The histologic type of this SPT is rare, so does it occurance at younger age and in a survivor with unilateral Retinoblastoma wihout a history of radiation therapy. The treatment of choice is combine surgery and chemo/radiation therapy, and the prognosis is poor.