Malignant spindle cell tumor arising in the mandible of a patient with florid osseous dysplasia.

Florid osseous dysplasia is a non-neoplastic condition of the alveolar processes of the jaws characterized by the replacement of multiple foci of bone by fibrous connective tissue, accompanied by gradual deposition of cementum, bone, or both. The lesions are not associated with inflammatory diseases of the dental pulp or periodontal tissues. In fully developed florid osseous dysplasia, there are multiple lobulated masses in the alveolar bone bilaterally in the mandible and sometimes in the maxilla. This is the first report of a malignancy originating within the jaws of a patient with florid osseous dysplasia. A spindle cell malignancy was diagnosed in the mandible of a 54-year-old black woman whose jaw was affected by florid osseous dysplasia bilaterally. Despite extensive surgery and radiotherapy, the patient died 20 months after diagnosis of the malignancy.