[Postradiation osteosarcoma in a patient with multiple myeloma].

The described patient presents a rare combination of primary and secondary malignant bone tumours. The primary bone tumour was histologically established as myeloma, and was treated by radiation and multiple-drug chemotherapy. The secondary tumour, histologically confirmed 19 years later, was osteogenic sarcoma occuring in the radiation field when clinical and laboratory examinations showed remission of the primary lesion. The age of the patient, the localisation of the second tumour in the radiation field, the latent period of elapsed years, histologic and radiographic evidence of the pre-existent osseous lesion (myeloma), indicate that the secondary tumour (osteogenic sarcoma) can be induced by irradiation.