Based on 3 cases of advanced testicular seminoma classified as stage IIC, the treatment of residual masses after chemotherapy is discussed. The excellent therapeutic response confirmed by histological study of the residual masses, which show a fibrotic or necrotic appearance, allows the adoption of a strategy using imaging techniques: either there is persistence of a gland mass syndrome and resection needs to be carried our or retroperitoneal fibrosis is visualised and careful follow up would appear to be sufficient.