Low-grade extraskeletal osteosarcoma is a rare tumor that may arise de novo or 
following radiation therapy. Because of the low-grade histology, it may be 
misdiagnosed as a benign lesion. We present a case of a 59-year-old man with a 
past history of radiotherapy for papillary carcinoma of the thyroid, presenting 
16 years later with a low-grade extraskeletal osteosarcoma of the neck. The 
patient was treated with surgical excision and is disease free after 12 months 
of follow-up. The prognosis for patients with low-grade extraskeletal 
osteosarcoma is relatively good when compared with high-grade sarcomas. While 
there is a report of a low-grade extraskeletal osteosarcoma arising following 
radiotherapy for a benign condition, to the best of our knowledge this is the 
first reported case of a low-grade extraskeletal osteosarcoma occurring 
following radiotherapy for thyroid cancer, and the only case reported in the 
soft tissue of the head and neck region.