A 48-year-old female with long-standing type 2 diabetes mellitus presented with acute onset of bilateral lower limb weakness. She had been previously well and denied any constitutional symptoms. Physical examinations revealed generalized lower limb weakness with bilateral lower limb hypotonia, power of 0 over 5, reduced deep tendon reflexes, and loss of peripheral sensations up to the level of T10. Upper limb functions were normal. Rectal examination showed a lax anal tone and reduced anal grip. Blood investigations showed elevated serum alkaline phosphatase, corrected serum calcium, and parathyroid hormone. Magnetic resonance imaging of the spine revealed an expansile mass at the posterior element of the ninth thoracic vertebrae, causing spinal compression with possible impingement of the right T9 exiting spinal nerve. An urgent surgical decompression and tissue biopsy were performed for stabilization of the spine. Intraoperative findings included spinal cord compression secondary to an epidural tumour mass extending from T9 to T10 disc levels. Histopathological analysis showed a giant cell tumour of the spine. A 99mTc Sestamibi-SPECT parathyroid scintigraphy showed an ectopic parathyroid adenoma at the left suprasternal region. A diagnosis of Brown tumour secondary to ectopic parathyroid adenoma was made. She underwent an exploratory parathyroidectomy procedure with removal of the ectopic parathyroid gland, which resulted in a normalization of the serum calcium and parathyroid hormone. Unfortunately, her lower limb functions did not return to normal, and she remained paraplegic at 6 months postoperatively.