Low‒Risk Essential Thrombocythemia Who Presented with Recurrent Episodes of Cerebral Hemorrhage during Pregnancy and Developed Cerebral Infarction during Puerperium.

A 42‒year‒old woman. At week 27 of pregnancy, she developed subcortical hemorrhage and underwent open cranial surgery for hematoma evacuation. The platelet(Plt)count was 297,000/μL. At week 34 of pregnancy, she developed subcortical hemorrhage again. The Plt count was 429,000/μL. At week 35 of pregnancy, the ventricular rupture and she underwent drainage and emergency cesarean section. The Plt count was 687,000/μL. Two days after delivery, hemorrhage was detected. The Plt count was 815,000/μL. Six days after delivery, she developed infarction. The Plt count was 915,000/μL. MRI revealed no evidence of aneurysm, arteriovenous malformations or tumor. Ten days after delivery, the Plt count was 1,173,000/μL. Bone marrow examination led to the diagnosis of essential thrombocythemia(ET). JAK2, CARL and MPL was negative. She was rated as"low‒risk"by IPSET‒thrombosis, and as"ultralow"risk by revised IPSET‒thrombosis. von Willebrand factor(VWF)activity was as high as 247%. The bleeding time and platelet aggregation activity were normal. There was no evidence of disseminated intravascular coagulation(DIC)or hypertensive disorders of pregnancy(HDP). She died of cerebral hemorrhage and infarction, 26 days after delivery.