Cauda equina syndrome-think of cancer.

Leptomeningeal carcinomatosis (LC) is a serious complication found in approximately 1% to 8% of patients with solid cancer and carries substantial rates of morbidity and mortality. Up to 48% of patients may present with LC before the presence of systemic cancer is known. We present the case of a patient who presented with symptoms of cauda equina syndrome and for whom subsequent investigations revealed intrathecal metastases and locally advanced lung cancer without respiratory symptoms or brain or bone metastases. The case emphasizes the need for thorough investigation in the presence of the triad: back pain, weakness in the lower extremities, and urinary urgency/incontinence. Cauda equina syndrome due to intrathecal metastases should always be considered. Spine MRI with contrast is the most informative investigative study for these patients, and myelography remains an important diagnostic method.