Bilateral malignant testicular germ cell cancer.

Twenty-six of approximately 1300 patients (1.9%) with unilateral testicular cancer developed a second primary germ cell cancer (seminoma 18; non-seminoma 8). Patients with previous seminoma had a significantly higher risk of developing a new seminoma than those with a previous non-seminoma. The diagnosis of second primary was made within 3 years of the first diagnosis in only 50% of the patients. In patients with a history of undescended and/or atrophic testes the interval significantly decreased between the diagnosis of the two testicular cancers. The prognosis of bilateral testicular cancer is generally good. Patients in whom the second testicular cancer is at clinical stage I (no metastases) at diagnosis can safely be observed without further treatment after orchiectomy. A patient with unilateral testicular cancer should be informed of the increased risk of developing a second primary germ cell tumour and should be encouraged to perform regular examination of the remaining testis. The need for life-long follow-up visits for patients with testicular cancer is questionable.