Dural based mass: malignant or benign.

In March 2007, a 68 year old female was diagnosed with colonic adenocarcinoma metastatic to the lungs and a frontoparietal parafalcine lesion suspected to be a meningioma was also noted. She denied neurologic symptoms and resection of the parafalcine lesion did not occur. For 14 months, she received chemotherapy with poor response. In June 2008, she developed multiple focal neurologic deficits. Enlargement of the parafalcine brain lesion was noted on head computerized tomography and magnetic resonance imaging. Cerebral angiogram demonstrated a parafalcine mass supplied by the middle meningeal artery. All 3 modality findings confirmed a meningioma. Embolization of the middle meningeal artery with craniotomy for excision of the suspected meningioma was performed. Pathology indicated metastatic adenocarcinoma with colonic primary without evidence of meningioma. Meningiomas are the most common dural based lesions; however, a variety of dural lesions mimic meningiomas. Dural metastatic tumors mimicking meningiomas is an uncommon phenomenon, particularly when the primary location is the colon. This paper additionally discusses the differentiation of benign dural based tumors like meningiomas from malignant findings. Multiple adjunct studies can differentiate meningiomas from metastatic tumor. The definitive diagnosis is based on histopathology.