RESUMO
A 61-year-old female, followed-up for a metastatic breast cancer, was admitted in our institution with conjunctival icterus, asthenia and abdominal crampoid pain. The patient was included in a clinical trial comparing the efficiency of capecitabine monotherapy versus capecitabine conjugated with a new biological agent in a randomised and double blind trial. The patient was in the capecitabine alone arm. Biological tests performed upon admission suggested the diagnosis of haemolytic anaemia. Moreover, the direct Coombs test result was twice positive indicating autoimmune haemolytic anaemia. Capecitabine has been reported to cause haemolysis either alone or combined with lapatinib, each time with a mechanism other than immunological. In this clinical case, capecitabine is the most likely factor causing an autoimmune haemolytic anaemia.