A Distinctive Pathologic Meningioma Completely without Enhancement and Dural Tail Sign on Imaging Findings

A Large Cavernous Sinus Giant Cell Tumor Invading Clivus and Sphenoid Sinus Masquerading as Meningioma: A Case Report and Literature Review

Giant cell tumor (GCT) of the bone is a rare benign, locally aggressive tumor that occurs in the epiphysis of long bones, especially the lower femur and the upper tibia. GCT of the bone of cranial origin is very rare, accounting for 1% of all GCT of the bone. We report the diagnosis, treatment, and immunohistochemistry of a rare case of intracranial GCT of the bone. We also review and summarize the imaging features, diagnostic markers, and current major treatment options for GCT of the bone. Our case and literature review emphasizes the importance of considering the full picture when making a diagnosis, rather than relying on imaging alone to make the diagnosis.

Absence of contrast enhancement in a petroclival meningioma: Case report and systematic literature review

Background:

Meningioma is one of the most common intracranial tumors with well-established radiologic features such as contrast enhancement, dural tail, and hyperostosis on computed tomography and magnetic resonance imaging. Contrast enhancement is usually homogeneous or heterogeneous based on tumor vascularity and underlying histopathology. Even in this context, faint or nonenhancing meningioma is exceedingly rare.

Case Description:

A 57-year-old male presented with progressive right hearing loss, disequilibrium, occasional difficulty swallowing, and facial numbness. Imaging demonstrated an extensive hypodense, nonenhancing right cerebellopontine angle mass extending from the interpeduncular, and ambient cisterns to the foramen magnum. The pathological analysis demonstrated a microcystic meningioma WHO Grade I. There are few reported case reports or series of minimal or nonenhancing meningiomas, and a systematic review was performed for these cases. Seven peer-reviewed articles with 14 verifiable cases were identified and reviewed for radiologic features, tumor location, and tumor classification. The majority of minimal or nonenhancing meningiomas were microcystic, and most of them located at the convexity. This is the second case reported of a nonenhancing meningioma at the cerebellopontine angle and petroclival region

Conclusion:

Meningioma should be considered a differential diagnosis for nonenhancing lesion at the cerebellopontine and petroclival regions.

Sylvian Fissure Meningiomas: Case Report and Literature Review

Meningiomas are primary intracranial tumors derived from arachnoid cap cells or meningothelial cells and usually display dural attachment. However, a small proportion of meningiomas that arise from the Sylvian fissure do not manifest dural attachment. Sylvian fissure meningiomas are relatively rare and have differential characteristics as compared with typical meningiomas. Herein, we reported a special case of atypical meningioma in the Sylvian fissure, that showed non-enhancement after contract management. The patient was a 30-year-old woman with a 2-year history of seizures. Preoperative computerized tomography and magnetic resonance imaging scans showed a calcific, non-enhancing lesion in the right insula lobe. The lesion was excised surgically for seizure control. Intraoperatively, the tumor was observed to be closely adhered to the middle cerebral artery (MCA), resulting in mild arterial damage. A case of Sylvian fissure meningioma was ultimately diagnosed by histopathological examination of the resected specimens. Sylvian fissure meningiomas are closely associated with the MCA and exhibit unusual imaging characteristics. Preoperative misdiagnosis may have serious adverse consequences and may result in incorrect surgery. To improve awareness of Sylvian fissure meningiomas on the differential diagnosis of Sylvian fissure lesions among clinicians, we present this report and briefly summarize previously reported cases to describe the clinical, pathological, radiological, and surgical features.