Abstract

BACKGROUND: Osteosarcomas (OS) of the jaws are uncommon lesions representing 6-8 of skeletal OS. We assessed the characteristics, demographics, prevalence clinical and histopathological findings and distribution of gnathic OS relative to non-gnathic OS in four major treatment centers. MATERIALS AND METHODS: This study assessed 13 gnathic OS patients of 98 OS patients from four major referral centers during 1996-2007. The age distribution, gender, involved site, clinical findings, signs, symptoms, grade and sub-types were assessed. Hematoxylin-eosin, Picrosirius red, Ponceau trichrome, Masson trichrome and osteoid staining methods were used. RESULTS: Of the 98 OS lesions, 85 (86.8) involved the skeleton, the youngest patient was 6 and the oldest 60 years old; 13 lesions (13.2) involved the jaws (seven mandibular and six maxillary) and the youngest and oldest patients were 15 and 50 years-old, respectively. Non-gnathic OS was more prevalent between the ages of 11 and 20 years (avg. 15 years) and was common in the distal femur and proximal tibia, presenting most frequently with pain and swelling. OS of the jaws, however, presented more than 10 years later than non-gnathic OS, being more prevalent between the ages of 20 and 30 years (avg. 27 years). OS of the jaws most frequently involved the mandibular body and the posterior maxillary alveolar ridge, presenting frequently with pain, swelling and loosening of teeth. Two patients with gnathic OS died during the 10-year follow-up period (15.3). CONCLUSION: Prevalence of OS of the jaws was about twice as high as that reported in other studies and presented later than non-gnathic cases. Pain and swelling were common signs and symptoms in this disease. The mixed sub-type was the most common sub-type of gnathic OS.