R. NICKBRYANMDPATRICIA A.HUDGINSMD
On microscopy, a tumor composed of osteoid-producing atypical osteoblasts was evident just beneath the skin, and the diagnosis of osteosarcoma was established. A thallium 201 scan did not reveal another hot spot. Treatment consisted of chemotherapy, followed by a radical mastoidectomy.
The osteosarcoma is best defined as a malignant tumor of mesenchymal cells characterized by the direct formation of osteoid or bone by the tumor cells. Some osteosarcomas are composed largely of fibroblastic cells, and others have abundant bone formation. Some show chondroid differentiation, and others are highly vascular (telangiectatic), but they all have tumor-produced osteoid formation marked by trapping of anaplastic tumor cells within the lacunae of the osteoid matrix.1,2
Radiology Quiz Case 2: Diagnosis. Arch Otolaryngol Head Neck Surg. 2005;131(10):926. doi:10.1001/archotol.131.10.926