An unusual case of severe acquired coagulopathy from cancer cachexia-related vitamin K deficiency.

Vitamin K deficiency is a well recognized cause of acquired coagulopathy, but its presentation as severe coagulopathy in the setting of advanced malignancy is not well described. We report a 67-year-old man with recurrent metastatic urothelial carcinoma and severe cachexia who presented with a markedly prolonged prothrombin time (PT) of 105.8 s and activated partial thromboplastin time (APTT) of 58.2 s. Hematologic evaluation revealed deficiencies in vitamin K-dependent clotting factors, and his coagulopathy corrected with intravenous vitamin K replacement. This case highlights that cancer cachexia itself can precipitate clinically significant vitamin K deficiency in patients with advanced malignancy leading to severe coagulopathy.