DOUBLE MALIGNANT NEOPLASMS OCCURRING LONG AFTER LOCAL RADIATION TO THE ORAL-MUCOSA

A 59-year-old woman who had received cobalt-60 (Co-60) interstitial ra diation therapy (total 44 Gy) in the right bucco-gingival region for i nflammatory pseudotumour was found to have metachronous double maligna nt neoplasms. Initial osteosarcoma of the right mandibular angle and s ubsequent squamous cell carcinoma of the right buccal mucosa were iden tified 28 and 33 years after the radiation, respectively. Since both t umours were located very close to the focus of previous radiation, the therapy was considered to be responsible for their genesis. The patie nt had systemic metastases of the osteosarcoma.