Primary Spine Tumors: Diagnosis and Treatment

Michelle J. Clarke, MD; Ehud Mendel, MD; Frank D. Vrionis, MD, PhD

Disclosures

Cancer Control. 2014;21(2):114-123. 

In This Article

Oncological Staging

By incorporating information about pathology, general morphology, and metastatic status of a lesion, generalizations about growth and behavior can be made in order to dictate the surgical approach. The Enneking classification[24] originally designed to stage limb lesions has been ported to primary spine tumors and provides an excellent overview (Table 3).[2,7,24–26]

Benign tumors are divided into 3 categories. S1 tumors are latent, asymptomatic, have a prominent capsule, and are often observed. An example of an S1 tumor is a schwannoma. S2 lesions are active with slow growth, mild symptoms, and a thin capsule or pseudocapsule of reactive tissue. Osteoid osteomas and smaller osteoblastomas fall into this category and can be treated with intralesional curettage unless marginal en bloc resection is achievable. S3 lesions are aggressive, demonstrate rapid growth, and often have a hypervascular pseudocapsule. Aggressive osteoblastomas are the hallmark of this type, and they may be treated with marginal en bloc resection. A "marginal margin" implies that the tumor pseudocapsule has not been violated; however, additional tissue is not included in the surgical specimen. This fact is important because spinal column tumors may reach the thecal sac, and a marginal margin can provide adequate treatment without neurological sacrifice (Fig 3).

Figure 3.

(A) A 34-year-old woman developed sudden back and radicular leg pain. A giant cell tumor with a pathological fracture was diagnosed via fine-needle aspirate biopsy. (B-D) Because these tumors have a high propensity for recurrence following intralesional resection, posterior and subsequent anterior en bloc resections and reconstruction were undertaken. The tumor between the great vessels was removed.

All malignant tumors require a wide en bloc resection. Although these lesions can be further categorized by location (whether confined to the vertebral body or within the paraspinal tissues) and whether islands of tumor are within the pseudocapsule or exist beyond the recognized pseudocapsule (low vs high grade), the pseudocapsule itself — unlike a benign tumor — cannot be considered a safe margin.[22] Originally described by Roy-Camille[27] for long-bone tumors, wide en bloc resection has been adapted to the spine. Due to the proximity of spinal cord and other vital structures to the axial spine, this procedure may not be feasible; however, limb amputation is recommended if necessary. Adjuvant therapy is generally recommended, particularly in cases of high-grade malignant lesions.

Patients with metastasis on presentation are candidates for palliative surgery and subsequent adjuvant therapy. The main goal of en bloc resection is to avoid local and distant seeding by violating the tumor. Thus, if a patient has metastases on presentation, en bloc resection is irrelevant, and the patient should be directed from a high morbidity procedure and instead toward adjuvant therapies, palliative debulking, and spinal stabilization.

Consideration for en bloc resection can also be provided to patients without evidence of metastases but in whom the tumor capsule was violated (eg, cases of previous resection or open biopsy) or in the presence of local recurrence. Although not ideal, it may be possible that local seeding has occurred and en bloc resection will lessen the likelihood of distant metastases. Due to local seeding, adjuvant therapy is usually recommended.

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