[Mediastinal seminoma. Is it an entity to be treated differently?].

The evolution of the therapeutic concepts of non seminomatous tumours (T) has chemotherapy as the preponderant treatment, and has also led to a different approach for mediastinal seminomas. In effect the traditional attitude for as complete an excision as possible followed by radiotherapy is in the process of changing. Certainly in 20% of cases a complete excision is possible. Post operative radiotherapy (30-50 grays) does not seem to change the survival and may be questioned in the management of invasive T. The radical debulking surgery of varying degrees no longer has a place. The standard treatment of inoperable T has remained for some time radiotherapy (35-40 grays). The survival at 5 years for these patients is around 60%, very close to the stage IIB seminoma of the testicles. If the seminoma seems to be radiosensitive it is also chemo-sensitive with an RC less than 80% in advance seminomas and of 90% in mediastinal seminomas. Thus there appears to be a contradictory debate; in the absence of precise staging of "thymic type" tumour and of randomised trials made difficult by the small number of cases one can envisage the following option: In the case of an inoperable T radiotherapy alone, excepting in the very bulky forms (diameter greater than 50% of the chest) or metastases where primary chemotherapy (CT) (4 cycles of VP16-platine) has a place: The treatment of the residual mass after CT depends on the size of the latter: less than 3 or equal to 3 cm by complementary treatment and greater than 3 cm by secondary surgery and if the seminoma is active complementary.(ABSTRACT TRUNCATED AT 250 WORDS)