An unusual presentation of telangiectatic osteosarcoma.

Telangiectatic osteosarcoma (TOS) is a rare subtype of osteosarcoma that accounts for approximately 2% of all osteosarcomas. Presented is a case of a sacral mass that was originally thought to be a chordoma and was treated surgically but on pathologic examination was diagnosed as a TOS. A review of the literature on other sacral lesions is provided. The intention for presenting this case is twofold: to make physicians aware of the differential diagnoses of sacral lesions and to report an unusual presentation of this rare tumor.