Endocrine secreting malignant mediastinal teratoma.

Malignant mediastinal teratoma containing yolk sac elements are rare tumours and invariably have a poor prognosis. An elevated alpha fetoprotein level is a useful indicator of the malignant nature and the invasiveness of the tumour. A case with such a tumour who also presented with precocious puberty is described. This patient was treated with radiotherapy and chemotherapy prior to radical surgical excision, and has now survived for over 64 months without evidence of metastases.