Tumor-induced Osteomalacia due to a Phosphaturic Mesenchymal Tumor in the Cervical Spine: A Case Report and Literature Review.

Tumor-induced osteomalacia (TIO) is a rare paraneoplastic syndrome of certain mesenchymal tumors which secrete fibroblast growth factor-23 (FGF-23) responsible for causing features of hypophosphatemia and osteomalacia in these patients. Most of them involve the appendicular skeleton and occasionally the craniofacial regions. Involvement of spine is exceedingly rare. Through this paper, the authors present a rare case of a 71-year-old male with TIO due to a lesion in the cervical spine (right C2 lamina) which was proven to be a phosphaturic mesenchymal tumor-mixed connective tissue type on histopathology. This is the fifth reported case of TIO localized to the cervical spine. The patient underwent a hemilaminectomy and gross total resection of the tumor following which he made a gradual but steady recovery and does not have any recurrence 24 months after surgery. The authors not only provide a comprehensive literature review of all 18 spinal cases reported till date but also discuss the management of these patients in light of the published literature.