Metastatic lobular breast adenocarcinoma presenting as cauda equina syndrome.

Dear Editor, Leptomeningeal carcinomatosis is a rare, but wellknown form of metastatic breast cancer, seen in up to 6% of breast cancer patients at autopsy (Tsukada et al., 1983). It most often occurs in the setting of a known primary malignancy and may present with signs and symptoms referable to anywhere along the neuroaxis. We report two patients who presented with isolated carcinomatous cauda equina syndrome. One of the patients did not have a known primary malignancy, whereas the other had localized breast cancer 20 years prior to evaluation. Both patients were suspected clinically to have a non-neoplastic etiology to their cauda equina syndrome; however, lumbar dorsal rootlet biopsies showed metastatic lobular breast adenocarcinoma. These cases demonstrate that metastatic breast cancer can present as isolated cauda equina syndrome, highlight the diverse presentations of metastatic malignancy, and reinforce the need for a broad differential diagnosis in this clinical setting.