We present a case of a patient with non-resected epidermoid carcinoma of the anal canal, treated with a combination of radiotherapy regional and chemotherapy according to MMC-Ufelos protocol. After the application of the fourth chemotherapy cycle, the patient presented microangiopathic hemolytic anemia associated to Mitomycin-C, which was treated with the application of recurrent plasmapheresis and restricted transfusions of red corpuscles concentrate. The physiopathology of this disorder and its therapeutical implications are review.