Introduction
As the most common malignancy, breast cancer is the second leading cause of mortality in women 1. Speaking of metastases, it has a special affinity for spine with around 67% of the diagnosed bone metastases occurring in spine 2. It is the most common cause of symptomatic spine metastases as one-third of them becomes symptomatic showing a spectrum of manifestations from lumbar pain to cord compression or cauda equina syndrome (CES) 3-5.
Disc sequestration, accounting for 28.6% of disc herniations, happens when a herniated disc migrates into the intracanal space with no link to the parent disc 6,7. Sometimes, the shape and place of a disc sequestrum (DS) can cause confusion in the radiologic diagnosis8. The differential diagnoses include tumors, abscess, hematoma, synovial cysts, and vascular lesions 7,9,10.
In this study, we have reported a case of CES caused by an epidural metastasis of breast cancer, which oddly mimicked a large disc sequestrum leading to misdiagnosis. To our knowledge, it is the first report of the direct metastasis of breast cancer to epidural space. We believe it is a cautionary case to remind in patients with known breast cancer, who present with disc herniation symptoms and MRI findings suggestive of a DS.