Osteofibrous Dysplasia

Summary
Description

Ossifying fibroma is a benign, non-metastasizing, fibrous tumor with local aggressive behavior. Lesions are most commonly found in the mandible for adults, and the tibia, along with other long bones, for children.

People and Age
The age range is broad, but usually occurs within the first decade of life.
Symptoms and Presentation
The tumor presents as a painless, enlarging mass.
Brief description of the xray
On x-ray, it has a distinctive image. The lesion is well circumscribed and has multi-loculated appearance, causing a distortion of the thin cortex.
Benign or Malignant
Most Common Bones
Periosteal reaction
Tumor behavior
Tumor density
Complete Information on this Tumor
Introduction and Definition

Ossifying fibroma, also known as osteofibrous dysplasia, is a benign fibrous tumor with local aggressive behavior. Ossifying fibroma does not metastasize.

Incidence and Demographics
The most common site in adults is the mandible. The most common site in children is the tibia, followed by other long bones. Ossifying fibroma occurs during the first decade of life.
Symptoms and Presentation

The tumor presents clinically as a painless, enlarging mass.

X-Ray Appearance and Advanced Imaging Findings
Ossifying fibroma has a distinctive radiologic picture. This lytic lesion occurs in the anterior cortex of the diaphysis or metaphysis of the tibia and often causes anterior-posterior bowing. This well-circumscribed tumor has a multi-loculated appearance and causes distortion of the thin cortex. Ossifying fibromas have increased uptake on bone scan.
Differential Diagnosis
The radiologic differential includes ad amantinoma, fibrous dysplasia, nonossifying fibroma and osteoblastoma.
Histopathology findings
Microscopically, ossifying fibroma consists of irregular spicules of trabecular bone lined by osteoblasts. These osteoblasts produce a rim of lamellar bone around centers of woven bone. Ossifying fibroma stains positive for cytokeratin.
Treatment Options for this Tumor
Treatment of ossifying fibroma in older patients includes conservative curettage. A thorough pathologic examination must be done for the presence of adamantinoma. Patients who still have open growth plates are observed. If bowing of the tibia becomes an issue, bracing is recommended.
Special and Unusual Features
The question has been raised if ossifying fibroma is a relative of fibrous dysplasia or a true neoplasm. Most recently, it has been surmised
that ossifying fibroma and adamantinoma are on a continuum with osteofibrous dysplasia-like adamantinoma representing an -intermediate step between the two lesions.
Suggested Reading and Reference
Springfield, DS et al., Relationship Between Osteofibrous Dysplasia and Adamantinoma, Clinical Orthopaedics and Related Research, 309:234-244, December, 1994.

Marks, KE and TW Bauer, Fibrous Tumors of Bone, Orthopedic Clinics of North America, 20(3):377-393, July 1989.

Bulloughs, Peter, Orthopaedic Pathology (third edition), Times Mirror International Limited, London, 1997.

Huvos, Andrew, Bone Tumors: Diagnosis. Treatment and Prognosis, W.B. Saunders, Co., 1991.
12/18/97