Acquired factor VIII inhibitor in a patient with adenocarcinoma of the lung.

A 58-year-old man developed an acquired factor VIII inhibitor in association with adenocarcinoma of the lung. Laboratory examinations showed a marked prolonged activated partial thromboplastin time and a low level of factor VIII activity. Further study revealed his serum to have a factor VIII inhibitor which was characterized as an IgG. Treatment with prednisolone was successful in reducing the inhibitor so that the bleeding manifested by epistaxis and subcutaneous hemorrhages in the extremities ceased. Circulating inhibitors against factor VIII associated with malignancies appear to be very rare. Fourteen patients with factor VIII inhibitors associated with malignancies were reviewed.