A neoplasm involving a cauda equina. The disease is cauda equina neoplasm (MONDO_0003164). Also known as: Cauda equina neoplasms, cauda equina neoplasm (disease), cauda equina tumor, cauda equina tumour, neoplasm of cauda equina, neoplasm of the Cauda equina, tumor of Cauda equina, tumor of cauda equina.