Atypical radiological and intraoperative findings of acute cerebral hemorrhage caused by ruptured cerebral aneurysm in a patient with severe chronic anemia.

Acute intracerebral hemorrhage (ICH) associated with mild anemia is commonly observed on radiological examination, and there are several reports of ruptured aneurysms occurring with ICH but without accompanying subarachnoid hemorrhage. However, the relationship among computed tomography (CT), magnetic resonance imaging (MRI), and intraoperative findings of ICH caused by ruptured cerebral aneurysm in patients with severe chronic anemia has been rarely reported and is poorly understood. Here, we report atypical radiological and intraoperative findings of acute ICH caused by ruptured cerebral aneurysm in a patient with severe chronic anemia. A 64-year-old man with anemia was admitted to our hospital after he experienced left hemiparesis and a disturbance of consciousness. At a referring institution, he showed evidence of macrocytic anemia (white blood cell count, 9,000/μL; red blood cell count, 104×10(4)/μL; hemoglobin, 4.0 g/dL; hematocrit, 12.2%; and platelet count, 26.6×10(4)/μL). Both CT and MRI showed a right frontal ICH. The outer ring of the hematoma appeared as low-density area on CT, a low-intensity area on T1-weighted MRI, and a high-intensity area on T2-weighted MRI with a serous component. The patient received a blood transfusion and underwent surgical removal of the hematoma the following day. The white serous effusion visualized with CT and MRI was identified as a blood clot in the hematoma cavity. The blood that leaks from blood vessels appears as a high-intensity area on CT because it undergoes plasma absorption in a solidification shrinkage process, and is, therefore, concentrated. Although we did not examine the white effusion to determine if serous components were present, we speculated that the effusion may have contained serous components. Therefore, we removed the part of the effusion that appeared as a low-density area on CT. The presence of ICH without subarachnoid hemorrhage suggested the possible adhesion and rupture of a previous aneurysm. Therefore, ICH appeared as a mixed density area on CT because bleeding may have occurred several times. Because radiological findings of ICH caused by ruptured cerebral aneurysm in patients with severe chronic anemia are similar to those of ICH and cerebral edema, we suggest that the atypical radiological findings of ICH caused by ruptured cerebral aneurysm in patients with severe chronic anemia should be carefully evaluated, especially when surgery is indicated.