Primary spine tumors are rare, accounting for only 4% of all tumors of the spine. A minority of the more common primary benign lesions will require surgical treatment, and most amenable malignant lesions will proceed to attempted resection. The rarity of malignant primary lesions has resulted in a paucity of historical data regarding optimal surgical and adjuvant treatment and, although we now derive benefit from standardized guidelines of overall care, management of each neoplasm often proceeds on a case-by-case basis, taking into account the individual characteristics of patient operability, tumor resectability, and biological potential. This article aims to provide an overview of diagnostic techniques, staging algorithms and the authors' experience of surgical treatment alternatives that have been employed in the care of selected benign and malignant lesions. Although broadly a review of contemporary management, it is hoped that the case illustrations given will serve as additional “arrows in the quiver” of the treating surgeon. Keywords: spinal tumors, primary tumors Primary neoplasms of the spine are rare. Although hamartomas (the group of non-neoplastic, ectopic cellular rests including hemangiomas and fibrous dysplasia) are considerably more common, few will ultimately require surgical treatment. Of all the primary musculoskeletal neoplasms, themselves rare conditions, primary spinal tumors represent 5% of all primary bone tumors, and the latter occur in 0.8 to 8.0 per 100,000 population. 1 2 4 A minority of the benign lesions will require operation. The more frequently encountered benign spinal tumors in surgical practice are osteoid osteoma and osteoblastoma, neural sheath tumors, aneurysmal bone cyst, benign fibrous tumor, giant cell tumor, and aggressive hemangioma. Malignant primary spinal tumors are even less common. In the United States there are ～600 new cases of primary spinal malignancy identified each year. 5 If identified at an amenable stage, with careful planning, most will be treated by attempts at resection. Primary musculoskeletal spinal malignancy includes chordoma, chondrosarcoma, osteogenic sarcoma (OGS), Ewing's sarcoma, and malignant peripheral nerve sheath tumor as well as plasmacytoma. Over a period of ～20 years, surgical capability in the realm of spinal tumor resection has been considerably enhanced by advances in anesthesia allowing for access to all spinal regions through multiple options, by improved collaboration with medical and radiation oncologist colleagues enabling multidisciplinary care pathways, and with the advent of magnetic resonance imaging (MRI), which allows more thorough staging and preoperative planning. Although resection strategy will ultimately be determined on a case-by-case basis, there are several constants in the planning of surgery. All vertebral resection surgery has an inexorable resection margin at the borders of the neural canal. Extirpation of tumors of the spinal column must, therefore, commonly divide the encircling ring around the neural elements, substantially complicating the compartmental model of musculoskeletal tumor management as described by Enneking. 12 Despite these limitations, the same biological principle of “adequate” excision to avoid local tumor recurrence holds true as reported by Weinstein, Boriani, and Biagini in their spinal adaptation of the work of Enneking. 2 7 As in any musculoskeletal site, adequate excision of a benign lesion, such as an osteoid osteoma, may be intralesional. In the case of primary malignancy of the spine, however, extirpation requires wide excision with often complex reconstruction over multiple vertebral levels. The location of the spinal neurological structures often calls for a balance between the aggression of complete tumor excision and the expediency of neural preservation. It is this balance that individualizes the surgery of spinal malignancy and from which has been borne the numerous more specialized resection techniques reported here. In general, spinal en bloc resection techniques are challenging procedures with a high rate of complication. For this reason, along with a high requirement for resources and the need for multidisciplinary care, referral to a specialized service in spinal oncology should be strongly considered.
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