We report a case of rhabdomyosarcoma which occurred in a mediastinal teratoma in a 44-year-old man. Presentation symptoms were chest pain, hoarseness and a cough. Diagnosis was fortuitous, performed by the histological and immunohistochemical study of a mediastinal tumour biopsy specimen that showed embryonal carcinoma and yolk sac tumour components associated with the rhabdomyosarcoma. After cisplatin-based chemotherapy (bleomycin-etoposide-cisplatin), surgical resection of the residual mediastinal tumour was performed. Histological and immunohistochemical study of this tumour confirmed the presence of mature teratoma and embryonal rhabdomyosarcoma. Evolution was marked by a local extension of the mediastinal tumour, occurrence of multiple metastases and bone marrow involvement. The patient died 8 months after diagnosis despite chemotherapy and radiotherapy. A review of the literature reveals that the development of rhabdomyosarcoma in primary mediastinal teratomas is unusual in adults. The diagnostic, therapeutic and prognostic implications of such an association are reviewed.
