Spinal cord tumor is useful to divide into three groups: extradural tumors, which usually arise in the bones of the spinal column or in the extradural space; intradural extramedullary tumors, which lie within the dura mater but side the spinal cord; and intramedullary tu originating within the substance of the Their comparative incidence in a general hos has been estimated at 50, 40, and 10 percent receptively
Extradural Tumors.
Although mention shouli be made of osteomas, chondromas, and chordomas,, the most important sources of these tumors art metastatic carcinomas from lung, breast, azii kidney, lymphomas, multiple myeloma, sarcomas prostatic carcinoma, arid cancer of the gastrointestinal tract, uterus, and thyroid, in order of importance. Focal spinal compression is the rule, although some of these neoplasms, particularly those from the reticuloendothelial system, may ensheath the cord by extensive infiltration of the extradural space.
Although the manifestations of extradural tumors depend on their localization, type, and size, their onset and progression is usually rapid because of their malignant nature. The patient will usually present weeks or months after the onset of symptoms. However, an acute onset with cord compression and prominent radicular symptoms can follow either the collapse of an involved vertebra or neoplastic invasion of the spinal vessels, producing infarction or hemorrhage within the tumor.
Severe pain from bone or nerve involvement is an early sign that can be accentuated by pressure over the corresponding vertebral spinous process. Occasionally a palpable spinal deformity will be encountered. The radicular symptoms are commonly bilateral and asymmetric. Spastic weakness below the lesion often precedes sensorv symptoms. Disturbed function of bladder and rectal sphincters generally occurs late in extramedullary tumors.
In diagnosis, particular care should be given to the examination of the lungs and breast when searching for a primary neoplasm. Anemia, bone pain, radiologic enlargement of the mediastinal shadow, hepatomegaly or splenomegaly suggests widespread metastatic disease or lymphoma. Skeletal changes, Bencet Jones protein in, the urine, morphologic examination of bone marrow, and serum electrophoresis help diagnose multiple myeloma. Bony changes will be present in 50 per cent of spinal roentgenograms taken at the time of onset of symptoms.
The earliest signs of vertebral involvement may be a slight decrease in density together with changes in the radiologic configuration of the body, transverse processes, arches, or pedicles. When plain roentgenograms are negative, evidence of bone involvement may be obtained by radioiosotopic scanning with strontium 85. Elevation of the cerebrospinal fluid protein and spinal blockage are often found on lumbar puncture. Myelography usually demonstrates the presence of an extradural mass which occasionally may be found somewhat distant from the site of visible bone destruction.
Radiotherapy, hormones, and chemotherapy may assist in controlling the skeletal lesions and prevent or reduce their compressive effects on the spinal cord. Surgical decompression is indicated for radio-resistant lesions or rapidly developing cord compression.
Extramedullary, Intradural Tumors.
These are commonly benign and present with a long history of unilateral radicular pain that prececes any signs of cord compression. Some tenderness 3n percussion of the neighboring verterrae may be present. The two most important tumors in this group are meningiomas and neurofinromas,
MeningsomesB are found mainly in middle-aged. 90 per cent occurring in the thoracic usually single, relatively small, arc :cater posterior or lateral to the spinal cord, to this position, meningiomas may produce ataxic spastic syndrome which resembles subacute combined degeneration. Pain is not usually prominent. Erosion of the pedicles and occasionally calcification of the tumor may be found on radiologic examination, but contrast myelography is required for accurate diagnosis.
Neurofibromas arise from the nerve roots, may develop at any age, and affect both sexes equally. They show no particular preference for any site within the spinal canal. In cases of neurofibromatosis of von Recklinghausen the typical skin pigmentation and the presence of multiple tumors along the peripheral nerves are diagnostic. A small percentage show sarcomatous degeneration. Occasionally a neurofibroma may arise within the substance of the spinal cord and behave as an intramedullary space-occupying lesion
Plain roentgenograms may demonstrate widening of the intervertebral foramen with dumbbell tumors. The radiologic changes may be out of proportion to the presenting symptoms because of an asymmetric development of the tumor, the intraspinai portion being relatively small in comparison to the extraspinal, which can grow to a considerable size and even be palpable. Myelography, as in all cases of intradural extramedullary tumors, is diagnostic. The cerebrospinal fluid shows an early elevation of protein content. Complete neurological recovery usually follows the surgical removal of meningiomas and neurofibromas.
Intramedullary Tumors.
The same histologic types of tumors that occur in the brain can involve the spinal cord, but with a different relative incidence. Ependymomas are most frequent, followed by astrocytomas, glioblastomas, oligodendrogliomas, vascular tumors, lipomas, and metastases.
Ependymomas can develop at any level but have a preference for the caudal region. They represent more than two thirds of the tumors that involve the conus medullaris, and are even more common in the filu.
. These neoplasms often produce an associated syringomyelia, making the clinical and radiologic findings more difficult to interpret. Although they occasionally bleed and give rise to acute, painful symptoms, the usual clinical course of intramedullary tumors is one of slow progression over several years. Pain at the level of the tumor is present, but usually is less severe and well localized than with extramedullary tumors. Impotence in males and sphincter disturbances in both sexes may be early symptoms, but the most common finding is that of a syringomyelic syndrome with muscle wasting and dissociated sensory loss. Anogenital or saddle anesthesia occurs when the lower spinal cord and cauda equina are involved.
Intramedullary tumors do not induce any radio-graphically visible changes in the walls of the spinal canal until fairly late in their course, at which time enlargement can be demonstrated by measurements of the width of the canal and identifying thinning of the pedicles. Contrast myelography usually demonstrates a typical spindle-shaped widening of the cord prior to any such bony changes. Surgical removal of some ependymomas is possible, whereas decompressive measures and radiotherapy may benefit others.
