Perisacral gastrointestinal stromal tumor with intracranial metastasis. Case report.

A 68-year-old woman presented with an extremely rare intracranial metastasis from a gastrointestinal stromal tumor (GIST) manifesting as left hemiparesis 2 years after resection of a sacral tumor adjacent to the coccygeal bone. Magnetic resonance imaging revealed an intracranial tumor in the right parietal lobe. Craniotomy was performed to completely remove the tumor. Although the tumor was located extra-axially, only internal carotid angiography showed mass staining. Seven months after surgery, the tumor recurred. Repeat craniotomy was performed to remove the recurrent tumor. Immunohistochemical analysis showed that the tumor cells were positive for c-kit and CD34, and the tumors were identified as intracranial metastasis of GIST. Following the second intracranial surgery, the patient developed severe lower back pain caused by metastatic tumor invading the lumbar spine and ureter. To avoid surgical complications and to reduce tumor volume, imatinib mesylate (Gleevec) was administered. The severe pain was relieved, although the tumor was not reduced. In this case, the extra-axial tumor was fed only by the internal carotid artery.