[Acquired FX deficiency: a case report and literature review]

Objective: To introduce the clinical features, laboratory findings, diagnostic approaches, and treatment of acquired factor X deficiency. Methods: This study reviewed a case of primary light-chain amyloidosis with acquired factor X deficiency admitted to our hospital. The patient's clinical course and diagnostic process were described, and a literature review was conducted. Results: The patient, a 69-year-old male, was admitted to our hospital due to abdominal bleeding. He was diagnosed with primary light-chain amyloidosis complicated by acquired factor X deficiency. Recurrent bleeding was attributed to amyloid deposits in peripheral blood vessels and organs, which adsorbed circulating factor X, causing its sequestration in the reticuloendothelial system (e.g. the spleen) and leading to decreased factor X levels. After active hemostasis and treatment of the underlying disease, the patient was discharged. Conclusion: This case provides insights and a reference for the diagnosis and management of the rare clinical presentation of acquired coagulation factor deficiency.