Bleeding complications after arthroscopy in a JAK2V617F-positive patient with essential thrombocythemia and acquired von Willebrand syndrome (AVWS)

Acquired von Willebrand Syndrome in a 17-Year-Old With Essential Thrombocythemia: A Case Report With Literature Review

Acquired von Willebrand syndrome (AVWS) is a rare bleeding disorder that is often underdiagnosed. AVWS typically occurs in adults without a family history of bleeding disorders and with associated conditions such as lymphoproliferative, myeloproliferative, and cardiovascular disorders. Here, we present a case of AVWS in a young patient with essential thrombocythemia and a literature review on AVWS in the setting of essential thrombocythemia.

Successful Chemical Synovectomy in a Patient with Acquired von Willebrand Syndrome with Chronic Synovitis Due to Recurrent Knee Hemarthrosis: A Case Report

Acquired von Willebrand syndrome (AVWS) is a rare, non-hereditary bleeding disorder related to heterogeneous medical conditions such as hematological malignancies and cardiovascular and autoimmune diseases. We describe the clinical course of a 62-year-old man with polycythemia vera who experienced post-traumatic knee and leg swelling due to hemarthrosis. He was treated at another center with low molecular weight heparin due to misdiagnosed deep vein thrombosis further exacerbating the ongoing bleeding. At our center, he was diagnosed with AVWS with reduced von Willebrand factor (VWF):GPIbR plasma activity and loss of high molecular weight multimers (HMWM). He was treated with compressive bandages with resolution. Five months later, on clinical recurrence of knee and leg swelling, knee ultrasound scan showed the presence of chronic synovitis and a hemorrhagic Baker's cyst with signs of rupture. The treatment consisted of chemical synovectomy with rifampicin and steroids preceded by systemic replacement therapy using plasma-derived factor VIII-VWF concentrate. At the end of the treatment cycle, our patient reported complete resolution of knee pain and restoration of joint range of motion and function. Ultrasound evaluation confirmed complete resolution of knee capsule distension and Baker's cyst. Hemarthrosis is an anecdotal presentation of AVWS and chemical synovectomy was successful in treating this complication. A multidisciplinary approach allowed an effective management of this rare complication.

Coexistence of Hermansky-Pudlak syndrome and JAK2V617F-positive essential thrombocythemia

Hermansky-Pudlak syndrome (HPS) is an autosomal recessive disorder consisting of oculocutaneous albinism, platelet storage pool deficiency, and lysosomal accumulation of ceroid lipofuscin. The storage pool deficiency of HPS is associated with the lack of dense bodies in the platelets, resulting in impaired response in the secondary phase of aggregation. Patients with HPS have normal coagulation tests; however, their bleeding time is usually prolonged despite normal or increased platelet counts. Essential thrombocythemia (ET) is an uncommon condition, with an incidence of approximately 1.1 per 100,000/year, and it is the most common cause of primary thrombocytosis. JAK2^V617F positivity can be observed in approximately half of the patients with ET. Bleeding events in ET have usually been associated with acquired von Willebrand syndrome paradoxically occurring when the platelet counts are extremely high. We, herein, present a case with bleeding diathesis diagnosed as having both HPS and JAK2^V617F-positive ET.