Oncogenic (Tumoral) Osteomalacia

Oncogenic osteomalacia occurs with bone or soft-tissue tumors and is characterized by renal phosphate wasting and hypophosphatemia and decreased serum 1,25-dihydroxycholecalciferol levels. Patients with rickets or osteomalacia unexplained by nutrition should be investigated for occult tumor.

Oncogenic osteomalacia is most frequently associated with the phosphaturic mesenchymal tumor, mixed connective tissue variant, but a search for more common tumors such as prostate, breast, small-cell carcinoma of the lung, fibrous dysplasia, and neurofibromatosis is also indicated.

Many cases of hemangiopericytoma leading to oncogenic osteomalacia are now thought to actually represent cases of phosphaturic mesenchymal tumor. In addition, the concept of hemangiopericytoma as a distinct entity has been called into question.

References

• Avila NA, Skarulis M, Rubino DM, Doppman JL. Oncogenic osteomalacia: lesion detection by MR skeletal survey. AJR Am J Roentgenol. 1996 Aug;167(2):343-5.
• Folpe AL, Fanburg-Smith JC, Billings SD, Bisceglia M, Bertoni F, Cho JY, Econs MJ, Inwards CY, Jan de Beur SM, Mentzel T, Montgomery E, Michal M, Miettinen M, Mills SE, Reith JD, O'Connell JX, Rosenberg AE, Rubin BP, Sweet DE, Vinh TN, Wold LE, Wehrli BM, White KE, Zaino RJ, Weiss SW. Most osteomalacia-associated mesenchymal tumors are a single histopathologic entity: an analysis of 32 cases and a comprehensive review of the literature. Am J Surg Pathol. 2004 Jan;28(1):1-30.
• Renton P, Shaw DG. Hypophosphatemic-osteomalacia secondary to vascular tumors of bone and soft tissue. Skeletal Radiol 1976; 5:21-24.