Significance of presence of teratomatous elements in the primary tumour of testicular cancer.

To assess the tumour aggressiveness of teratoma, clinical records of patients with non-seminomatous germ cell testicular cancer were reviewed. Teratomatous elements were found in 57.8% of tumours. The rate of stage I tumours was lower in the teratoma-positive group than in the teratoma-negative group. Lymph node metastasis occurred more frequently than haematogenous metastasis in the teratoma-positive group. Tumour marker response in metastatic stage of teratoma-positive group was very excellent. Even if the radiographic response was not good, most patients were alive without disease after postchemotherapeutic salvage surgery. Furthermore, two patients with pure teratoma, who had tumour recurrence, were successfully treated with the multimodal therapy. Considering the smaller number of stage I patients in the teratoma-positive group than in the teratoma-negative group, the excellent overall response in the teratoma-positive group showed less aggressiveness of the tumour as a whole.