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Chapter Summary
• Context: Benign spinal tumors and pseudotumoral lesions are frequently discovered as incidental radiographic findings, with many remaining asymptomatic. However, a 'benign' histological designation does not imply an indolent clinical course: aggressive osteoblastomas, aneurysmal bone cysts (ABC), aggressive vertebral hemangiomas, and giant cell tumors of bone (GCTB) can destroy osseous architecture, cause acute neurological deficits, and exhibit high local recurrence rates. Diagnostic reasoning requires synthesizing patient age, anatomical location (posterior elements vs vertebral body), clinical behavior, and multi-modality imaging on radiographs, CT, and MRI. The chapter emphasizes that when tissue diagnosis is warranted, image-guided biopsy must strictly obey oncological principles to prevent contaminating surgical corridors. Staging systems (Enneking, WBB) guide decision-making among observation, percutaneous embolization/ablation, intralesional curettage, and en bloc resection.
• Chapter Objective: To recognize clinical and imaging patterns of benign spinal tumors and pseudotumoral lesions, master the principles of biopsy and staging (Enneking, WBB), and formulate tailored therapeutic strategies for osteochondroma, osteoid osteoma, osteoblastoma, aneurysmal bone cyst, hemangioma, eosinophilic granuloma, and giant cell tumor of bone.
• Biopsy and staging principlesMultidisciplinary collaboration among the spine surgeon, radiologist, and pathologist is essential. Biopsies must procure viable diagnostic tissue through a tract that can be resected during definitive surgery. The Enneking classification differentiates latent (Stage 1), active (Stage 2), and aggressive (Stage 3) benign lesions, while the WBB system provides precise radial and layered anatomical mapping.
• Lesions of the posterior elementsOsteochondroma may be asymptomatic or cause canal stenosis and radiculomyelopathy (Figure 53.1). Osteoid osteoma presents with nocturnal pain relieved by NSAIDs and antalgic scoliosis, diagnosed by a radiolucent nidus on CT and treated percutaneously via CT-guided radiofrequency ablation (Figure 53.2). Osteoblastoma is larger (>1.5-2 cm) and more aggressive, requiring surgical resection and stabilization (Figure 53.3). Aneurysmal bone cysts (ABC) display multiloculated cystic cavities with fluid-fluid levels on MRI, treated via arterial embolization, sclerotherapy, denosumab, or curettage (Figure 53.4).
• Lesions of the vertebral bodyVertebral hemangiomas are common incidental findings displaying a 'polka-dot' or 'corduroy cloth' appearance; aggressive variants extend epidurally, requiring preoperative embolization and decompression (Figure 53.5). Eosinophilic granuloma (Langerhans cell histiocytosis) presents as pediatric vertebra plana, frequently resolving with conservative care or biopsy (Figure 53.6). Giant cell tumor of bone (GCTB) is histologically benign but biologically aggressive, carrying high recurrence rates and requiring en bloc resection or curettage with adjuvant denosumab (Figure 53.7).
• Therapeutic selectionLatent lesions require surveillance; active symptomatic lesions are managed with minimally invasive percutaneous techniques; and aggressive lesions demand complete resection and stabilization. The quality of the initial intervention determines local recurrence risk.
• Clinical Application: In clinical practice, evaluation starts by combining age, pain characteristics (e.g., aspirin-responsive nocturnal pain in osteoid osteoma), and anatomical epicenter (posterior arch vs vertebral body). CT is the gold standard for bony architecture, nidus identification, and matrix calcification; MRI defines soft-tissue extension and cord compression. Minimally invasive percutaneous techniques (CT-guided radiofrequency ablation for osteoid osteoma, transcatheter embolization for ABCs and aggressive hemangiomas) are highly effective but require prior diagnostic certainty. In aggressive osteoblastomas, ABCs, and giant cell tumors, post-treatment surveillance with serial MRI/CT is mandatory due to the risk of late recurrence.
