Introduction Meningiomas are the most common primary tumors, accounting for 35% of all intracranial neoplasms. Most are benign, clinically silent masses that are incidentally found on imaging as a solitary, focal lesion. However, there are reports of other extra-axial metastatic tumors in the dura and leptomeninges mimicking meningiomas that are misdiagnosed on imaging. Though rare, metastases to the dura have previously been characterized as late manifestations of an underlying primary malignancy and is associated with a poor prognosis. Metastases from a primary malignancy of the lung, breast, and prostate account for the majority of cases. However, dural metastasis from hepatocellular carcinoma (HCC) is extremely rare. Here we present a case of solitary, isolated dural metastasis from an underlying HCC mimicking a meningioma.

Methods N/A

Results Patient was a 64-year-old male who presented to the ED with 3 days of altered mental status and 12-day history of right sided weakness and dysarthria. Upon examination, there was presence of right hemiparesis with left gaze preference and was nonverbal and unable to follow commands. He was intubated for acute hypoxemic respiratory failure and was subsequently transferred to the ICU. MRI revealed a 5.8 cm enhancing left dural parafalcine hemorrhagic mass extending across the midline with significant vasogenic edema. and cerebral angiogram demonstrated the presence of a left ACA pseudoaneurysm within the mass receiving input from the left ophthalmic artery and right middle meningeal artery. The patient underwent embolization of the ACA pseudoaneurysm and resection of the parafalcine mass with no complications. Tumor pathology revealed a poorly differentiated carcinoma of the dura, consistent with metastatic hepatocellular carcinoma. The patient failed to demonstrate further neurological recovery and expired on day 18 of hospitalization.

Conclusions Solitary, isolated metastasis to the dura mater is a very rare manifestation of HCC and is seldom its initial clinical presentation. HCC initially spreads contiguously through the portal and hepatic veins followed by the regional lymph nodes. Intravasation into the veins subsequently leads to pulmonary vascular metastasis into the lungs, the most common extrahepatic metastatic site, followed by the bones and adrenal glands. The CNS is hypothesized to be the next most common site of HCC metastasis. Diagnosis of dural metastasis challenging as they are often difficult to distinguish from meningiomas on imaging. Both dural metastases and meningiomas may present as contrast enhancing, homogeneous lesions with a dural tail sign and vasogenic edema. Features specific to dural metastases include lower relative CBV on PWI and absence of alanine peaks on MR spectroscopy. Chronic subdural hematomas may also be present in 15-40% of cases. With advancements in cancer diagnoses and treatments resulting in increased survival time, it is crucial to remain aware of the possibility of dural metastasis masquerading as a meningioma.

Disclosures J. Choi: None. Y. Zhang: None. F. Hui: None. S. Brown: None. S. Tsappidi: None.