Clinical and bone density outcomes of tumor-induced osteomalacia after treatment.
OBJECTIVE
To report the outcomes of tumor-induced osteomalacia after treatment, particularly related to recovery of bone mass.


METHODS
We review the clinical course of a 61-year-old man extremely debilitated from multiple fractures and neuromuscular weakness due to tumor-induced osteomalacia and report the changes in biochemical markers and bone density after removal of the causative neoplasm.


RESULTS
At the time of diagnosis, the patient's serum phosphorus and 1,25 dihydroxyvitamin D levels were depressed, and his fibroblast growth factor-23 level was markedly elevated. These values normalized 2 days after surgery and remained within their respective reference ranges 4 and 12 months after resection of a mesenchymal tumor. Lumbar bone density values (T-scores) were 0.445 g/cm2 (-5.9) preoperatively, 0.939 g/cm2 (-1.4) 4 months after surgery, and 1.152 g/cm2 (0.7) 12 months after surgery. Left femoral neck values at the same time points were 0.525 g/cm2 (-3.0), 1.035 g/cm2 (-0.8), and 1.184 g/cm2 (1.9). Ultra-distal radius values at the same time points were 0.128 g/cm2 (-7.0), 0.191 g/cm2 (-5.9), and 0.259 g/cm2 (-4.8). In addition, he recovered neuromuscular function and was able to leave his wheelchair.


CONCLUSIONS
Tumor-induced osteomalacia can be an extremely debilitating disease. With successful localization, identification, and resection of the neoplasm, bone mass and physical function can recover.
Umphrey
Lisa G
LG
The Department of Internal Medicine, Mayo Clinic Scottsdale, Scottsdale, Arizona 85260, USA.
Whitaker
Michael D
MD
Bosch
E Peter
EP
Cook
Curtiss B
CB
D015519:Bone Density; D004185:Disability Evaluation; D000089703:Fibroblast Growth Factor-23; D005346:Fibroblast Growth Factors / Q000097:blood / Q000378:metabolism; D050815:Fractures, Compression / Q000000981:diagnostic imaging / Q000209:etiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008637:Mesenchymoma / Q000150:complications* / Q000175:diagnosis / Q000601:surgery; D008875:Middle Aged; D018198:Mixed Tumor, Malignant / Q000150:complications / Q000175:diagnosis / Q000601:surgery; D018908:Muscle Weakness / Q000209:etiology; D010018:Osteomalacia / Q000000981:diagnostic imaging / Q000209:etiology*; D010257:Paraneoplastic Syndromes / Q000000981:diagnostic imaging / Q000209:etiology*; D049268:Positron-Emission Tomography; D011859:Radiography; D020127:Recovery of Function; D012983:Soft Tissue Neoplasms / Q000150:complications* / Q000175:diagnosis / Q000601:surgery
D005346:Fibroblast Growth Factors; D000089703:Fibroblast Growth Factor-23