Histological and immunohistochemical findings in a fatal case of thrombotic thrombocytopenia after ChAdOx1 nCov-19 vaccination

: This case report describes a fatal case of a young woman with superior sagittal, transverse and sigmoid sinus thrombosis after administration of the ChAdOx1 nCov-19 vaccination. Eleven days post-vaccination she was found unconscious and transferred to the Emergency Department. Blood parameters showed low platelets, and a CT scan showed an extensive left intracranial hemorrhage and the presence of an occlusive thrombus of the superior sagittal sinus. She under-went a craniectomy, but after the intervention, she remained in a comatose state. After a few days, her clinical conditions worsened, and she died. A complete autopsy was performed which showed a thrombosis of the cerebral venous district, of the upper and lower limbs. A blood sample was also performed to carry out a gene study about the predisposition to thrombosis. The organ samples were studied through light microscope both in hematoxylin-eosin and immunohistochemical examination, and showed a strong inflammatory response in all samples and at the site of thrombosis. Our study aims to provide a proper autopsy technique to study the entire cerebral venous system through a multidisciplinary approach (anatomical dissection and neurosurgery) in post-vaccine venous thrombosis.