[A new case of leydigioma of the testis (author's transl)]

A new case of leydigioma, seen in a young adult, poses the problem of the long term prognosis of an apparently benign tumour of this type. The usefulness of routine complementary carcinological therapy associating radio-surgery and immunotherapy is discussed. In fact, such treatment was rejected in favour of strict surveillance, possible in a cooperative subject, involving clinical examination every three months and endocrine studies and a chest X-ray every 2 months.