NICK R.BRYANMDPATRICIA A.HUDGINSMD
Histopathologic examination of the biopsy specimen revealed an abundant mineralized lacy osteoid formed by moderately anaplastic cells, suggestive of osteoblastic osteosarcoma (Figure 3). A few osteoclastic giant cells were observed at the periphery of the tumor. Small foci of the tumor showed a spindle cell pattern.
Osteosarcoma is the most common malignant bone tumor that develops in individuals before the age of 40 years.1 However, it is an extremely uncommon tumor, occurring in only 1 in 1 00 000 persons per year in the United States.2 It predominantly affects the appendicular skeleton. In the head and neck, the behavior of osteosarcoma differs considerably from its long-bone counterpart, the cause of which is poorly understood because of its rarity in head and neck. Only 6% of all osteosaracomas occur in the jaw.3 The incidence of osteosarcoma of the jaw is 0.07 cases per 100 000 persons per year.4 Osteosarcoma of the jaw is twice as common in males as in females and presents around the fourth decade of life, an onset that is 1 to 2 decades later than that of long-bone osteosarcoma. Our index case occurred in the second decade of life. In a series of 66 cases of osteosarcoma of the jaw that were reported by Clark et al,5 only 15% of the cases presented in the second decade of life. Osteosarcoma of the jaw has higher survival rates than its long-bone counterpart. The 5-year survival rate is approximately 25% for maxillary osteosarcoma and 41% for mandibular osteosarcoma.4 This is explained by the fact that 44% of the jaw osteosaracomas are low grade; on the other hand, only 20% of long-bone osteosaracomas are low grade.5 The pathogenesis is not known. Predisposing factors include prior irradiation, Paget disease of bone, fibrous dysplasia, retinoblastoma, and Li-Fraumeni syndrome. Our patient did not have any predisposing factors. Osteosarcoma of the jaw is almost equally distributed between the maxilla and the mandible. Clark et al5 reported occurrence rates of 51% and 49% in the maxilla and the mandible, respectively. Survival is better in cases of mandibular tumor.4
Radiology Quiz Case 4—Diagnosis. Arch Otolaryngol Head Neck Surg. 2004;130(12):1450. doi:10.1001/archotol.130.12.1450