Toxic Osteoblastoma

Toxic osteoblastoma is an extremely rare variant of osteoblastoma that is associated with systemic symptoms, such as fever, anorexia, weight loss. There is also marked systemic periostitis, not only of the involved bone, but also at other skeletal sites.

Patients tend to be young children (5-7 years of age). On physical examination, there is massive swelling, warmth, and induration of the overlying skin and prominent superficial vessels overlying the lesion. Patients can also have hyperdynamic circulation and even high-output cardiac failure. Regional adenopathy can also be present.

The systemic response is thought to be due to an exaggerated immune response to the tumor. Interleukins can lead to fever and the diffuse periostitis, as well as anemia and massive limb swelling and vascular proliferation. Another possibility is toxic substances released by the tumor itself.

The lesions are highly vascular, and arteriovenous shunting within the lesion can lead to finger clubbing and diffuse periostitis and can account for hyperdynamic circulation.

Differential considerations include osteomyelitis and osteosarcoma.

References

• Dale S, Breidahl WH, Baker D, Robbins PD, Sundaram M. Severe toxic osteoblastoma of the humerus associated with diffuse periostitis of multiple bones. Skeletal Radiol. 2001 Aug;30(8):464-8.
• Mirra JM, Cove K, Theros E, Paladugu R, Smasson J. A case of osteoblastoma associated with severe systemic toxicity. Am J Surg Pathol. 1979 Oct;3(5):463-71.
• Theologis T, Ostlere S, Gibbons CL, Athanasou NA. Toxic osteoblastoma of the scapula. Skeletal Radiol. 2007 Mar;36(3):253-7.