Osteoblastoma in the fibula

Epiphyseal osteoblastoma of tibia with xanthomatous stromal reaction

Osteoblastoma occurring in long bones has a distinctive predilection for the metaphysis and the diaphysis. Epiphyseal location is rare. Although variation in histologic patterns is a well-known feature of this tumor, xanthomatous stromal reaction has not yet been described. We report a case of a 34-year-old man who developed an osteoblastoma primarily located in the epiphysis of his left tibia with extension into the metaphysis. The striking histologic features included a prominent xanthoma-like stroma consisting of foamy histiocytes in addition to focal areas with classical configuration of an osteoblastoma. The significance of this finding is discussed.

Periosteal osteoblastoma of the distal humerus

We present the case of a 12-year-old patient with periosteal osteoblastoma in the distal humerus. The clinical, pathological, and imaging findings are described and discussed.