Acquired factor X deficiency in a patient with multiple myeloma: a rare case highlighting the significance of comprehensive evaluation and the need for antimyeloma therapy for bleeding diathesis.

Factor X deficiency is a rare bleeding disorder that can be associated with life-threatening bleeding events. Factor X deficiency can either be inherited or acquired. Acquired cases of factor X deficiency can be seen in patients with plasma cell dyscrasias as well as amyloidosis. Coagulopathy, with clinically relevant bleeding events, although rare, is not an unusual phenomenon for patients with systemic amyloidosis. However, clinically relevant bleeding in patients with symptomatic multiple myeloma, without associated amyloidosis, has not been reported in literature before. We present a rare case of multiple myeloma without concomitant amyloidosis that presented with life-threatening bleeding from acquired deficiency of factor X and responded remarkably to treatment for underlying multiple myeloma. This case not only highlights the diagnostic workup required in patients with factor X deficiency but also provides the principles of management of acquired coagulopathy in plasma cell dyscrasias. © BMJ Publishing Group Limited 2019. No commercial re-use. See rights and permissions. Published by BMJ.