Paraparesis As a Rare First Presentation Of Primary Hyperparathyroidism-Related Brown Tumor in The Thoracic Spine: Case report and literature review.

Introduction And Importance: Brown tumor (BT) is defined as osteolytic lesion of an underlying state of hyperparathyroidism. Hyperparathyroidism will activate osteoclasts which initiate active bone resorption foci of lytic-cysts with hemosiderin depositions that pigment it with its characteristic brown pathologic gross appearance. Devastating fractures and injuries can occur to affected bones and surrounding tissue that require emergent intervention and correction.

Case Presentation: We present a case of a medically free 31-year-old female patient, who presented complaining of unsteadiness and progressive lower limbs weakness over 40 days of duration. Subsequent lab tests showed elevated PTH levels, along with 3.5 × 1.8 cm heterogeneous soft tissue mass involving the right pedicle on T7 level compressing the corresponding level of the spinal cord. Surgical management aimed to decompress the spinal cord and to obtain a biopsy for histopathologic examination which revealed a brown tumor. Neck ultrasound and Sestamibi scan indicated the presence of hyperactive and hyperplastic parathyroid tissue most suggestive of parathyroid adenoma.

Clinical Discussion: Various presentations of Brown Tumor depend on the bone affected, despite the rarity of spinal involvement, yet expanding tumors can manifest either with back pain, radicular pain, paresthesia, weakness, paralysis, or incontinence. The highest incidence rates of spinal brown tumors affect adults over the age of 40. Management goals are to decompress the neuronal tissue emergently and to prevent further bony lytic deterioration.

Conclusion: The objective of this study is to provide an overview of primary hyperparathyroidism-related spinal brown tumors, presentation, and summary of previously reported similar cases in the literature.