Post-irradiation leiomyosarcoma. Case report with immunohistochemical studies

We report here one case of post-irradiation leiomyosarcoma. The diagnosis of this was confirmed using anti-intermediate filament antibodies: tumor cells were positive for anti-vimentin and anti-desmin but negative for anti-prekeratin and anti-epithelial membrane antigen. The positive staining with anti-desmin clearly indicates a muscular origin although the tumor cells were not stained by two anti-actin antibodies, one directed against alpha-smooth muscle actin and the other against alpha-striated muscle actin. Irradiation was motivated by a wrong diagnosis of breast carcinoma when the patient was 13 year-old. The laps of time separating irradiation and the occurrence of the leiomyosarcoma was 13 years. The total dose was 6,000 rads. This is the ninth case of post-irradiation leiomyosarcomas reported in the literature.