Non-traumatic rupture of the spleen and marked post-splenectomy thrombocytosis associated with polycythemia vera

A man in his sixties presented to the ER with severe abdominal pain. When he awoke in the morning, he felt a dull pain in the periumbilical area, which extended to the right hypochondrial area in the daytime. The pain exacerbated and became accompanied by cold sweats. On examination, his consciousness level was normal. His body temperature was 37.2℃, pulse rate was 113 beats/min, respiration rate was 12 breaths/min, blood pressure was 135/85 mmHg, and arterial oxygen saturation was 95%. His abdomen was distended, but no rebound tenderness or muscular defense was observed. The patient had no trauma or triggering events. The patient initially presented to the Department of Hematology 4 years earlier with polycythemia. His red cell count at the time was 9.21 * 10 6/μL, hemoglobin was 20.7 g/dL, hematocrit was 66.8%, mean corpuscular volume was 73 fL, mean corpuscular hemoglobin was 22.5 pg, white cell count was 18.7 * 10 3/μL, and platelet count was 404 * 10 3/μL. The level of lactate dehydrogenase (LD) was 628 U/L, iron was 43μg/dL, and erythropoietin was 0.8 mIU/mL (reference range, 4.2-23.7 mIU/mL).