Preoperative Assessment of Pathologic Subtypes of Meningioma and Solitary Fibrous Tumor/Hemangiopericytoma Using Dynamic Computed Tomography: A Clinical Research Study.

BACKGROUND: Solitary fibrous tumors (SFTs)/hemangiopericytomas (HPCs) are highly vascularized tumors well known for malignant, invasive, and highly vascular features. To date, several studies have reported the preoperative imaging findings of SFTs/HPCs. In this study, computed tomography (CT) tumor values acquired from dynamic CT scan were selected to determine the tumor pathology of highly vascular tumors, such as SFTs/HPCs. METHODS: We conducted a retrospective study on patients with pathologically diagnosed meningiomas and SFTs/HPCs who had undergone a dynamic contrast CT scan. We assessed and compared the CT values of these tumors according to the pathology. RESULTS: From a total of 34 patients, 30 patients with meningiomas and 4 patients with HPCs were included. The mean CT values of SFTs/HPCs and angiomatous meningioma were statistically significantly higher than those of the other meningioma subtypes (P = 0.003). We also performed receiver operating characteristic curve analyses to detect an appropriate cutoff point for the CT value to differentiate tumor pathology, and the calculated threshold was 161 Hounsfield units (HU) (sensitivity, 100%; specificity, 75%; area under the curve, 0.87; 95%, CI 0.75-0.99). CONCLUSIONS: This study showed that obtaining a CT value is useful in determining highly vascular tumor pathology preoperatively. When considering neurosurgical extra-axial tumor removal, and when the CT value of tumors is >161 HU, then highly vascular tumors such as SFTs/HPCs or angiomatous meningiomas are likely, and this should be considered prior to surgical intervention and for risk assessment.

A case report of surgical management of hemangiopericytoma at the foramen magnum.

BACKGROUND: Hemangiopericytoma (HPC) is a highly vascularized mesenchymal tumor known for its high rates of recurrence and metastasis. The extent of tumor removal is known to be the most trustful prognostic factor. Skull base HPCs are challenging to treat because of the difficulty of the surgical approach and proximity to vital vascular and neuronal structures. We successfully treated a case of HPC at the ventral foramen magnum through surgical gross tumor removal via a far-lateral transcondylar approach. CASE DESCRIPTION: A 38-year-old male complained of neck pain and bilateral paresthesia of his shoulders for 2 months, for which he was referred to our hospital. A magnetic resonance image (MRI) showed a 20 mm diameter mass at the ventral foramen magnum, which compressed his medulla oblongata. The tumor was gross totally removed via a far-lateral transcondylar approach. During the surgery, marked bleeding disturbed the surgical field until the main feeding artery from the direction of the dura mater was coagulated and cut. A relatively wide surgical field and a transcondylar approach were helpful to control the bleeding. The pathological examination revealed the tumor to be a HPC. After an uneventful recovery period of 9 days, the patient was discharged without neurological sequelae. CONCLUSION: We successfully and completely removed an HPC near the foramen magnum, employing a wide surgical field and a transcondylar approach to help control bleeding. When the tumor is suspected preoperatively to be a hemangiocytoma or vascular-rich tumor, a surgical approach that can secure a wide surgical field should be selected.