Periosteal osteoblastoma of the distal femur

Abstract

Osteoblastomas located on the surface of the cortical bone, so-called periosteal osteoblastomas, are extremely rare. We report on a case of periosteal osteoblastoma arising from the posterior surface of the right distal femur in a 17-year-old man. Roentgenographic, computed tomographic, magnetic resonance imaging, and histologic features of the case are presented. Periosteal osteoblastoma should be radiologically and histologically differentiated from myositis ossificans, avulsive cortical irregularity syndrome, osteoid osteoma, parosteal osteosarcoma, periosteal osteosarcoma, and high-grade surface osteosarcoma. Although periosteal osteoblastoma is rare, this tumor should be included in the differential diagnosis of surface-type bone tumors.

Surface primary bone tumors: Systematic approach and differential diagnosis

“…It is typically discovered on the posterior elements of the vertebral column in males who are 10-30 years old, and pain, local tenderness and swelling are the most common presenting symptoms [10].…”

“…When osteoblastoma arises in the long tubular bones, the metaphysis and the diaphysis of the femur and tibia are preferentially involved [10,11]. Unlike osteoid osteoma, osteoblastoma displays progressive growth and has malignant potential [10].…”

“…4a) [10,11]. The intense perilesional sclerosis seen in osteoid osteoma is absent, but sometimes perilesional sclerosis is obvious.…”

“…The intense perilesional sclerosis seen in osteoid osteoma is absent, but sometimes perilesional sclerosis is obvious. Cortical erosion and periosteal reactive new bone are rare [10].…”

“…In the scanty case reports in which the MRI appearance of periosteal osteoblastoma was described, the tumor was isointense to muscle on T1-weighted images, hyperintense or heterogeneous with low and high signal intensity on T2-weighted images, and showed moderate or intense enhancement after contrast medium administration [10,11]. Sometimes the surrounding soft tissues and medullary cavity showed markedly high signal intensity on T2-weighted images (Fig.…”