Neoplastic epidural spinal cord compression (ESCC) is a common complication of cancer that can cause pain and potentially irreversible loss of neurologic function. The degree of thecal sac compression required for the designation of ESCC has been variably defined; we and others consider any radiologic evidence of indentation of the thecal sac to be evidence for ESCC [1,2].
In adults, the tip of the spinal cord usually lies at the L1 vertebral level; below this level, the lumbosacral nerve roots form the cauda equina, which floats in cerebrospinal fluid (CSF). Since the pathophysiology of compression of the thecal sac at the level of the cauda equina does not differ significantly from that of more rostral compression, compression of the cauda equina is still generally referred to by the slightly inaccurate name of ESCC.
The epidemiology, pathophysiology, clinical features, and diagnosis of ESCC will be reviewed here. The treatment and prognosis of this disorder are discussed separately. (See "Treatment and prognosis of neoplastic epidural spinal cord compression, including cauda equina syndrome".)
Many cancer patients have asymptomatic or unrecognized ESCC, while others develop ESCC after the decision has been made to forgo extensive diagnostic testing or therapy. For these reasons, the incidence of this complication can only be estimated. One population-based study of spinal cord compression reported that the likelihood of a patient with cancer suffering cord compression in the five years before death was 2.5 percent, ranging from 0.2 percent in pancreatic cancer to 7.9 percent in myeloma . A study of malignant spinal cord compression in hospitalized patients with cancer identified an annual incidence of 3.4 percent .
Autopsy studies suggested that 5 percent of patients dying with cancer have ESCC . Similar findings were noted in a Danish study based upon referrals to a regional treatment center, in which the incidence of ESCC in cancer patients rose from 4.4 to 6 percent between 1979 and 1985 .