Primary osteosarcoma of the thoracic spine: report of an unusual elderly patient with autopsy findings.

Abstract

A case report of primary osteosarcoma of the spine in an elderly patient. The histopathological features of osteosarcoma vary widely, often leading to diagnostic difficulties particularly when there is little evidence of osteoid formation. The report describes the difficulty in the diagnosis of osteosarcoma of the thoracic vertebra. Department of Orthopaedics and Rehabilitation Medicine, Fukui University Faculty of Medicine, Fukui, Japan. A 78-year-old man presented with paraparesis and underwent urgent anterior excision of a primary spinal tumor emanating from the T10 vertebra followed by artificial vertebral replacement. The patient eventually died of disseminated disease of vertebral osteosarcoma. Samples from the T10 vertebral tumor showed neoplastic growth of atypical spindle-shaped cells, with foci of storiform-like proliferation. The tissue also demonstrated positive immunohistochemical staining for vimentin and alpha-smooth muscle actin and a tentative diagnosis of leiomyosarcoma was made. However, a metastatic nodule of the chest wall at autopsy showed focal osteoid formation, a finding not seen in the primary tumor. Early detection and accurate diagnosis is important for improving not only patient prognosis but also the quality of life. We should always consider this rare entity, particularly in elderly patients who present with back pain and vertebral collapse.