Disseminated Leptomeningeal Carcinomatosis (Lc); Presenting with Cauda Equina-Conus Syndrome

Intradural extramedullary(intrathecal) metastases; a subtype of leptomeningeal carcinomatosis (LC), constitute approximately 4-6% of spinal metastases. They most commonly represent drop metastases from accompanying intracranial secondary lesions that become entangled within the nerve roots of the cauda equina. Generally, they occur as a late complication. However, there are some cases related to cauda equina syndrome (CES) that are the first presentation of primary malign lesion. We present the case of a patient who presented with symptoms of cauda equina-conus syndrome and for whom subsequent investigations revealed diffuse lumbar intrathecal metastases and locally advanced lung cancer without brain 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.