High-titer acquired factor V inhibitor responsive to corticosteroids and cyclophosphamide in a patient with two malignant tumors.

We report a 79-year-old man with two simultaneous malignant tumors (buccal epidermoid carcinoma and prostatic adenocarcinoma) who developed a severe bleeding complication at the site of the buccal tumor as well as a massive cerebral hematoma after a skull trauma. Laboratory findings showed the presence of a high-titer specific factor V inhibitor. The patient failed to respond to intravenous immunoglobulins, but both clinical and laboratory improvement was obtained after treatment with corticosteroids and cyclophosphamide.