2026 年 13 巻 p. 493-498
Intratumoral hemorrhage caused by metastatic brain tumors originating from intimal sarcoma is extremely rare. We report a diagnostically challenging case of cerebral metastasis from a left atrial intimal sarcoma that initially presented as subcortical hemorrhage in a young adult. A 24-year-old woman presented with right homonymous hemianopia and was diagnosed with a subcortical hemorrhage in the left parietal lobe. No obvious source of bleeding was identified, and the patient was managed conservatively and discharged. One month later, fever, dyspnea, and palpitations developed in the patient. Echocardiography revealed a large mass in the left atrium. Brain imaging indicated a mass-like lesion within the prior hematoma cavity, suggesting that the hemorrhage might have been secondary to an underlying neoplasm. After surgical removal of the cardiac tumor, the patient experienced recurrent bleeding in the left parietal lobe and underwent emergency craniotomy for hematoma evacuation. Histopathological analysis of the resected lesion confirmed metastasis involvement from a primary left atrial intimal sarcoma. Although the patient underwent radiotherapy for the left parietal and cardiac lesions followed by systemic chemotherapy, she died 8 months after the initial diagnosis. This case highlights the importance of considering intratumoral bleeding in cases of spontaneous intracerebral hemorrhage without an identifiable cause. Comprehensive follow-up using multiple imaging and systemic evaluations is essential for early detection and accurate diagnosis.
