Bilateral germ cell tumours of the testis.

Between 1952 and 1976, 760 men with testicular tumours were seen at The Royal Marsden Hospital. Of this group 21 (2.75%) developed tumours of the contralateral testis, in 2 instances synchronously and in the remaining 19 at intervals from 4 months to 15 years. Of 15 men in whom adequate history has been obtained, 7 (46%) had a history of maldescent and in all 7 patients the pathology of both tumours showed the same histological subtype. Only one example of malignant teratoma undifferentiated (MTU) as first tumour was encountered; 13 of 19 (68%) patients had seminomas and the second tumour was a seminoma in 11 patients (58%). Of the group of 21 patients, 12 (57%) are alive and disease-free. Of 14 Stage I patients (second tumour), 12 (85%) are considered cured of their 2 tumours. However, patients with evidence of extratesticular spread did badly, even if the second tumour was a seminoma, and treatment for these patients should include chemotherapy. Similarly, both Stage I MTU second tumours did badly.