A 26-year-old woman with
neurofibromatosis presented with worsening left hip
pain. Magnetic resonance imaging showed a large left paraspinal mass, subtotal resection of which confirmed PNST. Despite chemo-
radiation therapy, the
tumor progressed over 16 months, requiring
tumor debulking and L3-4 lumbar
laminectomy. The patient developed progressive bilateral lower extremity weakness due to direct
tumor invasion of the lumbosacral vertebrae with concurrent
hypercalcemia. Ionized
calcium was 1.47 mmol/dL (reference range is 0.95 to 1.32 mmol/dL), PTH was <4.0 pg/mL (reference range is 8 to 85 pg/mL),
25-hydroxyvitamin D was 14 ng/mL,
calcitriol was <8.0 pg/mL (reference range is 18 to 78 pg/mL),
PTHrP was 40 pg/mL(reference range is 14 to 27 pg/mL), urinary
calcium was <2.0 mg/24 hours, serum
C-telopeptide was 1,008 pg/mL (reference range is 64 to 640 pg/mL), and bone-specific
alkaline phosphatase was 15.7 μg/L (reference range is 4.7 to 17.8 μg/L). Her serum
magnesium,
phosphorus, and
creatinine levels were normal. Intravenous
zoledronic acid and hydration resulted in a normal ionized
calcium. Additional imaging revealed extensive
tumor invasion of L3-S1 vertebrae. Due to her poor response to all
cancer therapies, the patient was discharged to home hospice services.
CONCLUSION: