Navigation-assisted resection of tumoral calcinosis of the lumbosacral spine: illustrative case

BACKGROUND: Tumoral calcinosis is an uncommon disease resulting from dystrophic calcium phosphate crystal deposition, with only 7% of cases involving the spine, and it may diagnostically mimic neoplasms. OBSERVATIONS: In this case, a 54-year-old woman with history of systemic scleroderma presented with 10 months of progressive left lumbosacral pain. Imaging revealed an expansile, 4 × 7-cm, well-circumscribed mass in the lumbosacral spine with L5–S1 neuroforaminal compression. Because intractable pain and computed tomography (CT)-guided needle biopsy did not entirely rule out malignancy, operative management was pursued. The patient underwent L4–S2 laminectomies, left L5–S1 facetectomy, L5 and S1 pediculectomies, and en bloc resection, performed under stereotactic CT-guided intraoperative navigation. Subsequently, instrumented fusion was performed with L4 and L5 pedicle screws and S2 alar-iliac screws. Pathological examination was consistent with tumoral calcinosis, with multiple nodules of amorphous basophilic granular calcified material lined by histiocytes. There was no evidence of recurrence or neurological deficits at 5-month follow-up. LESSONS: Because spinal tumoral calcinosis may mimic neoplasms on imaging or gross intraoperative appearance, awareness of this clinical entity is essential for any spine surgeon. A review of all case reports of lumbosacral tumoral calcinosis (n = 14 from 1952 to 2016) was additionally performed. The case featured in this report presents the first known case of navigation-assisted resection of lumbosacral tumoral calcinosis.