A 58-year-old female presented to the emergency room with dark-colored stools, exertional shortness of breath and generalized weakness.Her past medical history included immune thrombocytopenic purpura (ITP) which was diagnosed several years prior to the current presentation (exact date unknown). Because of refractoriness to steroids, she was treated with rituximab and showed a good clinical response for a few years. She underwent splenectomy seven years ago due to relapsed ITP, which resulted in normalization of her platelet count.However, after 2 years, she developed recurrent thrombocytopenia with platelet count of 28 3 10 9 /L and mild elevation in liver function tests. This prompted a computed tomographic (CT) scan of the abdomen which revealed an accessory spleen that was removed. She also received another treatment with rituximab at that time with improvement in platelet count. This produced a prolonged normalization of platelet counts and she did well until this acute presentation with gastrointestinal bleeding. Her physical examination was unremarkable except for pallor in mucous membranes. Her complete blood count (CBC) showed white blood cell (WBC) count of 8.6 3 10 9 /L, hemoglobin (Hb) 7.6 g/dl and platelets of 326 3 10 9 /L. Her prothrombin time (PT) and activated partial thromboplastin time (aPTT) were normal.Peripheral smear showed normocytic normochromic anemia, consistent with post-hemorrhagic anemia, borderline neutrophilia and normal platelet number with post-splenectomy changes, including moderate anisopoikilocytosis and Howell-Jolly bodies. The platelets showed preserved granularity and appropriate variability of size. Esophagogastroduodenoscopy showed erythema of the stomach with 8 mm bleeding polyp which was cauterized and removed.Though the patient had a history of ITP, due to normal platelet count and peripheral smear morphology on presentation, her bleeding was attributed to the structural lesion in the stomach and she was discharged home after stabilization of bleeding.She presented to her hematologist one month later, and complained of frequent nose bleeds and easy bruising. She was evaluated by an ENT physician who did not find any exposed vessel that would explain the epistaxis. This raised concern for a hematologic disorder that was causing epistaxis. CBC done in clinic showed a WBC count of 8.7 3 10 9 /L, Hb of 12.5 g/dL, platelet count of 382 3 10 9 /L and MCV 87.6 fL. The patient's samples were sent to our institution for diagnostic evaluation, including platelet aggregation studies.Since the CBC showed normal platelet count and peripheral smear was normal, we performed the coagulation screening tests (PT, aPTT) followed by a von Willebrand panel [von Willebrand factor antigen (VWF:Ag), ristocetin cofactor (VWF:RCo), and factor VIII activity (FVIII)]. The coagulation screening tests showed normal results with PT of 12.5 seconds (normal range 12.0-15.5 seconds) and aPTT of 31 seconds (normal 24-35 seconds). Von Willebrand panel indices were proportionately elevated: VWF:Ag of 256%...