Spinal cord astrocytomas are uncommon tumors that present unique diagnostic and therapeutic challenges. Surgical intervention carries significant risk, but has the potential to offer both diagnostic and therapeutic benefit. Tumor-related morbidity and mortality remains high, despite continued research into the field.
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• Clinical symptoms are often insidious and nonspecific.
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• Spinal astrocytomas are rare entities, but carry high associated morbidity and mortality.
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• Treatment options are limited, but surgical intervention can offer diagnostic and therapeutic benefit.
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• Better understanding of the etiology and molecular biology will hopefully lead to safer and more effective therapies.
Historical note and terminology
In 1888, William Gowers and Victor Horsley described the first diagnosis and removal of an intradural spinal tumor. However, it was not until over 20 years later that Elsberg and Beer described the first removal of an intramedullary tumor utilizing both a laminectomy and midline myelotomy (22). Progress remained limited in subsequent years, however, due to the rarity of cases, the limits in diagnostic technology, and the high morbidity of intervention. Greenwood reported on 6 patients who underwent complete removal of intramedullary ependymomas (29), but half developed significant neurologic disability.
Significant advances have been made in subsequent years. The advent and dispersion of MRI technology has greatly aided in detecting these tumors early on in their course. In addition, advances in neurooncology have aided in classification and genetic profiling. Moreover, improvements in surgical tools and microsurgical technique have allowed for safer and more complete resection, leading Epstein and colleagues in the 1980s to report apparent cures in low-grade tumors, especially in children (23; 20; 24; 18).
Despite these advances, however, many of the key points outlined in the initial reports about intramedullary spinal tumors remain true to this day. As Greenwood recommended in 1954, when attempting complete removal of the tumor, the important factors are: “surgery [should] be carried out before paralysis is too far advanced; [… the tumor] should be of such consistency that it can be handled without damage to the cord; […] a good plane of cleavage between the spinal cord and the tumor; […] gentleness that does not exceed the elastic limit of cord tissue” (29). For infiltrating astrocytomas of the cord surgical resection is often not feasible (and may not be of value) and only a biopsy for diagnostic purposes is performed.