Leptomeningeal Carcinomatosis Presenting as Cauda Equina Syndrome

A 47-year-old female presented with subacute onset progressive backache, severe lancinating pain radiating to lower limbs, and bowel/bladder dysfunction over a period of 2 months duration. On examination, she had flaccid paraplegia, areflexia, and sensory loss in lower limbs. Diagnosis of severe cauda equina syndrome was considered. Magnetic resonance imaging (MRI) lumbosacral (LS) spine T2 sagittal images showed thickening and clumping of LS roots leading to the obliteration of cerebrospinal fluid (CSF) space. Contrast-enhanced MRI demonstrated intense enhancement of LS nerve roots and meninges [Figure [Figure1a1a and andb].b]. Lumbar puncture resulted in dry tap due to LS root hypertrophy and CSF space obliteration. Positron emission tomography-computed tomography (PET-CT) showed linear hypermetabolic ill-defined soft tissue in spinal canal, raising suspicion of malignancy [Figure 1c]. Histopathology and immunohistochemistry of meningeal biopsy arachnoid matter were suggestive of undifferentiated carcinoma [Figure 2]. Diagnosis of leptomeningeal carcinomatosis was confirmed. However, the primary source of malignancy was not detected in this patient