A 48-year-old woman from the Maghreb came to the emergency department with insidious gait difficulties, urgency, and constipation starting 6 months prior to the visit. The patient's complaints consisted of weakness, stiffness, and pain in her legs. Her medical history consisted of Hashimoto thyroiditis and breast cancer, with the latter having motivated surgery 4 months prior to admission. Histopathologic examination had demonstrated ductal cancer sensitive to estrogen and mapping with sentinel node biopsy ruled out metastasis. For that reason, the patient was treated with local radiation given weekly over 1 month and treatment with tamoxifen was started. Physical examination upon admission demonstrated weakness and spasticity in both legs. Reflexes were brisk; bilateral nonsustained foot clonus and Babinski sign were also present. Bilateral dorsal flexion was reduced, but vibration and sensation to touch and pinprick were normal. Sphincter tonus was reduced; systemic manifestations such as myalgias, fever, skin rashes, uveitis, sicca, and arthritic joints were absent.