Extraskeletal osteosarcoma in the neck. A case report and review of the literature

Extra skeletal osteosarcoma is a rare neoplasm characterized by the formation of a malignant osteoid. This condition is usually described in patients aged greater than expected for other intraosseous osteosarcomas, and the thigh is the most common site. We report a clinical case of a 19-year-old female patient and review the literature. The patient present with a mass in the right side of the neck and paraesthesia of the upper limbs. The mass corresponded to an extraskeletal osteosarcoma. We discuss the clinical findings, image findings (conventional radiographs, computed tomography, magnetic resonance imaging), histopathology results and differential diagnosis of this condition. (author)