Extradural spinal cord tumor
Arise in vertebral body or epidural tissue.
Extradural tumors are usually metastatic and most often arise in the vertebral bodies.
1. metastatic: comprise the majority of ED tumors
a) most are osteolytic (cause bony destruction): see Spinal epidural metastases
Common ones include:
● lymphoma: most cases represent spread of systemic disease (secondary lymphoma); some cases may be primary
b) metastases that may be osteoblastic:
● in men: prostate Ca is the most common
● in women: breast Ca is the most common
2. primary spinal tumors (very rare)
a) chordomas
d) aneurysmal bone cyst (ABC): an expansile tumor-like osteolytic lesion consisting of a highly vascular honeycomb of blood-filled cavities separated by connective tissue septa, surrounded by a thin cortical bone shell which may expand. Comprise 15% of spine tumors.
Etiology is controversial. May arise from preexisting tumor (including: osteoblastoma, giant cell tumor, fibrous dysplasia, chondrosarcoma) or following acute fracture. In the spine, there is a tendency to involve primarily the posterior elements. Peak incidence is in the second decade of life. Treatment usually consists of intralesional curettage. High recurrence rate (25–50%) if not completely excised
e) chondrosarcoma: a malignant tumor of cartilage. Lobulated tumors with calcified areas
f) osteochondroma (AKA chondroma AKA osteocartilaginous exostosis): benign tumors of bone that arise from mature hyaline cartilage. Most common during adolescence. An enchondroma is a similar tumor arising within the medullary cavity
g) vertebral hemangioma
h) giant cell tumors (GCT) of bone: AKA osteoclastoma
i) giant cell (reparative) granuloma: AKA solid variant of ABC.5 Related to GCT. Occurs primarily in mandible, maxilla, hands and feet, but there are case reports of spine involvement.5,6 Not a true neoplasm—more of a reactive process. Treatment: curettage. Recurrence rate: 22–50%, treated with re-excision
j) brown tumor of hyperparathyroidism
k) osteogenic sarcoma: rare in spine
3. miscellaneous
a) plasmacytoma
c) unifocal Langerhans cell histiocytosis (LHC), née eosinophilic granuloma: osteolytic defect with progressive vertebral collapse; LHC is one cause of vertebra plana. C-spine is the most commonly affected region. Individual LHCs associated with systemic conditions (Letterer-Siwe or Hand-Schüller-Christian disease) are treated with biopsy and immobilization. Collapse or neurologic deficit from compression may require decompression and/or fusion. Low-dose RTX may also be effective.
d) Ewing’s sarcoma: aggressive malignant tumor with a peak incidence during the second decade of life. Spine mets are more common than primary spine lesions. Treatment is mostly palliative: radical excision followed by RTX (very radiosensitive) and chemotherapy
e) chloroma: focal infiltration of leukemic cells
f) angiolipoma: ≈ 60 cases reported in literature
g) neurofibromas: most are intradural, but some are extradural, usually dilate neural foramen (dumbbell tumors)
h) Masson’s vegetant intravascular hemangioendothelioma