Cell-free Circulating DNA in Primary Cutaneous Lymphomas

To evaluate the possibility of detecting cell-free circulating tumoral DNA in potentially aggressive primary cutaneous lymphomas, the investigator opted to search a representative tumor sample mutation in the blood of these patients, by digital PCR. Patients with mycosis fungoides, primary cutaneous T-cell lymphoma helper follicular phenotype and primary cutaneous diffuse large B-cell lymphoma, leg-type will be included and 4 blood samples will be collected during 12 months.