Cauda Equina Syndrome Secondary to Diffuse Infiltration of the Cauda Equina by Acute Myeloid Leukemia: A Case Report and Literature Review

Abstract Background Cauda equina syndrome (CES) results from the dysfunction of the lumbar, sacral, and coccygeal rootlets composing the cauda equina. The underlying etiology is most commonly compression secondary to a large herniated lumbosacral disc; however, any pathology affecting the rootlets can result in the syndrome. We present a rare case of CES secondary to neoplastic polyradiculitis in a patient with acute myelogenous leukemia (AML) and review the pertinent literature. Case Presentation A 72-year-old male with a past medical history of AML presented with two-weeks of difficulty with ambulation followed by the acute-onset of low back pain radiating to the buttocks bilaterally. Imaging of the lumbar spine demonstrated diffuse enhancement and thickening of the cauda equina rootlets. Lumbar puncture showed numerous blasts with monocytoid features consistent with AML, and the patient was diagnosed with polyradiculopathy of the cauda equina secondary to diffuse metastatic infiltration. Conclusion Central nervous system (CNS) involvement of leukemia is poorly understood, even though such lesions are not uncommon in advanced disease. As treatment has improved, many types of leukemia, such as AML, are believed to be curable, and patients with the disease are living longer. With improved survival, it is reasonable to suspect that such involvement by AML may become more common. Our patient is a classic presentation of CES secondary to diffuse infiltration by AML and serves as an example of this rare manifestation of hematologic malignancy.