Antiphospholipid syndrome followed idiopathic retroperitoneal fibrosis in the same patient: A case report and review of literature

Abstract Introduction Idiopathic retroperitoneal fibrosis (IRPF) is a rare fibro‐inflammatory disease characterized by fibrous sclerosis of the retroperitoneal area and may be accompanied by other autoimmune diseases. Herein, we report an unusual case of IRPF with compression of retroperitoneal vessels, then diagnosed with antiphospholipid syndrome (APS), evidenced by multiple venous thrombosis and persistent positivity of antiphospholipid antibodies (aPLs). Along with literature reviews, we highlighted the importance of screening for all possible causes in case of thrombosis secondary to IRPF. Case Description A 46‐year‐old male patient was admitted in 2010 due to hypogastralgia and low back pain. The initial laboratory findings showed elevated inflammatory indicators, but negative results of immunology screening. Abdominal computed tomography (CT) revealed diffuse soft tissue in the retroperitoneal area. IRPF was first diagnosed and initially treated with glucocorticoids and immunosuppressants. Along the process of tapering the drugs, IRPF relapsed again. Reexamination of CT scan showed newly developed thrombus in the retroperitoneal vessels. APLs were evaluated and persistently positive with the interval of six months. The diagnosis of APS was confirmed. Glucocorticoids and immunosuppressants were prescribed again accompanied with warfarin. During 17‐month follow‐up periods, there was no relapse of symptoms again. Conclusion When IRPF is accompanied by venous thrombosis, in addition to blood flow stasis due to venous compression, other potential causes of thrombophilia should also be considered.