Spontaneous major bleeding in acquired factor X deficiency secondary to AL-amyloidosis.

Abnormal bleeding may be seen in up to a third of patients with amyloidosis. Factor X deficiency is the commonest acquired coagulopathy in amyloidosis. While mild intracutaneous bleeding is common, spontaneous life-threatening haemorrhage is rare. We report a case of acquired FX deficiency due to amyloid light chain (AL)-amyloidosis presenting with spontaneous retroperitoneal bleeding. The diagnostic and management issues in this patient are discussed.