Spontaneous omental bleeding presenting as acute abdomen during treatment for polycythemia vera

: A 54-year-old woman with polycythemia vera (PV) presented as an emergency patient with acute abdomen. Her platelet count was 119 x 10(4)/microl. Computed tomography scan revealed fluid accumulation in the omentum and peritoneal space. An emergency laparotomy was undertaken because of severe abdominal pain and omental bleeding was diagnosed. Peritoneal hemorrhage and hematoma weighing in total 1040 g was drained. Although a part of the omentum and stomach was excised, we could not find any orifice from which bleeding could have occurred despite a thorough pathological examination. Massive hemorrhage should be considered in cases with PV presenting as acute abdomen, especially when the platelet count is extremely high (over 100 x 10(4)/microl).