PET/CT imaging of giant primary pulmonary meningioma: a case report and literature review.

BACKGROUND: An ectopic meningioma, such as a primary pulmonary meningioma (PPM), is a rare type of tumor that primarily originates outside of the central nervous system. The most common presentation of PPM is isolated pulmonary nodules or masses, and most of them are benign. Only sporadic cases have been reported. This case reported a giant primary pulmonary meningioma and systematically reviewed previously reported cases in the literature. CASE PRESENTATION: A 55-year-old female suffered from asthma after activity, chest tightness, and a persistent dry cough for 2 months. Chest computed tomography (CT) showed a huge mass with calcification in the left lower lobe. And positron emission tomography (PET)/CT revealed mild FDG accumulation of the mass. The mass was finally surgically removed and PPM was confirmed according to histopathologic examinations. CONCLUSION: PPM is a rare disease with heterogeneity not only in CT features but also in glucose metabolism. FDG uptake levels do not identify benign from malignant, benign PPM may have high FDG uptake and malignant may have low.

Medical Management of Meningiomas.

Meningiomas represent the most common type of benign tumor of the extra-axial compartment. Although most meningiomas are benign World Health Organization (WHO) grade 1 lesions, the increasingly prevalent of WHO grade 2 lesion and occasional grade 3 lesions show worsened recurrence rates and morbidity. Multiple medical treatments have been evaluated but show limited efficacy. We review the status of medical management in meningiomas, highlighting successes and failures of various treatment options. We also explore newer studies evaluating the use of immunotherapy in management.

Open Surgical Approaches for Meningiomas.

Meningiomas are the most common intracranial extra-axial primary tumor. Although most are low grade and slow growing, resection can be technically challenging, particularly when located at the skull base. Appropriate craniotomy and approach selection are of paramount importance to minimize brain retraction, optimize exposure, and achieve complete resection. This article summarizes various craniotomies and their approaches to meningiomas, and illustrates some nuances in performing these techniques with cadaveric dissection and operative videos.

Advanced Meningioma Imaging.

Noninvasive imaging methods are used to accurately diagnose meningiomas and track their growth and location. These techniques, including computed tomography, MRI, and nuclear medicine, are also being used to gather more information about the biology of the tumors and potentially predict their grade and impact on prognosis. In this article, we will discuss the current and developing uses of these imaging techniques including additional analysis using radiomics in the diagnosis and treatment of meningiomas, including treatment planning and prediction of tumor behavior.

Incidental Meningiomas: Potential Predictors of Growth and Current State of Management.

The rise in availability of neuroimaging has led to an increase in incidentally discovered meningiomas. These tumors are typically asymptomatic and tend to display slow growth. Treatment options include observation with serial monitoring, radiation, and surgery. Although optimal management is unclear, clinicians recommend a conservative approach, which preserves quality of life and limits unnecessary intervention. Several risk factors have been investigated for their potential utility in the development of prognostic models for risk assessment. Herein, the authors review the current literature on incidental meningiomas, focusing their discussion on potential predictive factors for tumor growth and appropriate management practices.

Histopathologic and Molecular Evaluation of Meningioma.

Meningiomas are the most common intracranial tumor. This article reviews various aspects of the pathology of these tumors, from their frozen section appearance to the various subtypes a pathologist may come across at the microscope. Special emphasis is placed on the importance of CNS World Health Organization grading by light microscopic means to predict biological behavior of these tumors. Furthermore, relevant literature concerning the potential impact that DNA methylation profiling of these tumors and the possibility that this molecular testing modality might be the next step in refinement of our analysis of meningioma is presented.

Endovascular Embolization of Intracranial Meningiomas.

Although benign in histology, the hypervascularity and skull base location of meningiomas can make them surgically challenging lesions. Preoperative endovascular embolization with superselective microcatheterization of vascular pedicles may be efficacious in decreasing intraoperative transfusion requirements with equivocal postoperative functional benefit. The potential benefits of preoperative embolization should be weighed against the risks of ischemic complications. Appropriate patient selection is critical. All patients should be monitored closely postembolization, and a course of steroids can be considered to minimize neurologic symptoms.

Management of Atypical and Anaplastic Meningiomas.

Meningiomas are the most prevalent primary tumor of central nervous system origin, and although most of these neoplasms are benign, a small proportion exemplifies an aggressive profile characterized by high recurrence rates, pleomorphic histology, and overall resistance to standard treatment. Standard initial therapy for malignant meningiomas includes maximal safe surgical resection followed by focal radiation. The role for chemotherapy during recurrence of these aggressive meningiomas is less clear. Prognosis is poor, and recurrence of malignant meningiomas is high. This article provides an overview of atypical and anaplastic "malignant" meningiomas, their treatment, and ongoing research looking for more effective treatments.

Management of Intraventricular Meningiomas.

Intraventricular meningiomas (IVM) are intracranial tumors that originate from collections of arachnoid cells within the choroid plexus. The incidence of meningiomas is estimated to be about 97.5 per 100,000 individuals in the United States with IVMs constituting 0.7% to 3%. Positive outcomes have been observed with surgical treatment of intraventricular meningiomas. This review explores elements of surgical care and management of patients with IVM, highlighting nuances in surgical approaches, their indications, and considerations.

Endoscopic Endonasal and Keyhole Surgery for Skull Base Meningiomas.

Traditionally, resection of anterior skull base meningiomas has been achieved by transcranial approaches; however, morbidity related (ie, brain retraction, sagittal sinus damage, optic nerve manipulation, and cosmetic healing) represent a limit of the approach. Minimally invasive techniques including supraorbital and endonasal endoscopic approaches (EEA) have gained consensus as surgical corridors provide direct access to the tumor via a midline approach in carefully selected patients . The supraorbital approach requires some retraction of the rectus gyrus, but it offers minimal risk of postoperative CSF leak or sinonasal morbidity compared to EEA.

Spheno-Orbital Meningiomas.

Meningiomas are the most common intracranial brain tumor. Spheno-orbital meningiomas are a rare subtype that originate at the sphenoid wing and characteristically extend to the orbit and surrounding neurovascular structures via bony hyperostosis and soft tissue invasion. This review summarizes early characterizations of spheno-orbital meningiomas, presently understood tumor characteristics, and current management strategies.

The Role of Radiotherapy in the Treatment of Higher-Grade Meningioma.

High-grade meningiomas (atypical and anaplastic/malignant) are at increased risk of recurrence following primary treatment with maximum safe surgical resection. Evidence based on several retrospective and prospective observational studies suggests an important role of radiation therapy (RT) in both adjuvant and salvage settings. At present, adjuvant RT is recommended for incompletely resected atypical meningiomas and anaplastic meningiomas irrespective of resection extent with disease control benefit. In completely resected atypical meningiomas, the role of adjuvant RT remains debatable but should be considered given the aggressive and resistant nature of recurrent disease. Randomized trials are currently underway and may guide optimal postoperative management.

Spinal Meningiomas: Diagnosis, Surgical Management, and Adjuvant Therapies.

Meningiomas of the spinal canal are the most common intradural spinal canal tumors encountered in adults and account for 8% of all meningiomas. Patient presentation can vary considerably. Once diagnosed, these lesions are primarily treated surgically, but depending on location and pathological features, chemotherapy and radiosurgery may be required. Emerging modalities may represent adjuvant therapies. In this article, we review the current management of meningiomas of the spinal column.

Novel Systemic Approaches for the Management of Meningiomas: Immunotherapy and Targeted Therapies.

Meningiomas, the most prevalent primary intracranial tumor, arise from the arachnoid cap cells in the meninges, the membranes that surround the brain and the spinal cord. The field has long sought effective predictors of meningioma recurrence and malignant transformation, as well as therapeutic targets to guide intensified treatment such as early radiation or systemic therapy. Novel and more targeted approaches are currently being tested in numerous clinical trials for patients who have progressed after surgery and/or radiation. In this review, the authors discuss relevant molecular drivers that have therapeutic implications and examine recent clinical trial data evaluating targeted therapies and immunotherapies.

High-Value Care Outcomes of Meningiomas.

High-value health care has become a widely researched topic within neurosurgery. The concept of "high-value" care involves optimizing resource expenditures relative to patient outcomes, and therefore, high-value care research within neurosurgery has involved identifying prognostic factors for outcomes such as hospital length of stay, discharge disposition, monetary charges/costs incurred during hospitalization, and hospital readmission. The following article will discuss the motivation of high-value health-care research for optimizing the surgical treatment of intracranial meningiomas, highlight recent research investigating high-value care outcomes in patients with intracranial meningioma, and explore future avenues for high-value care research in this patient population.

Stereotactic Radiosurgery for Intracranial Meningiomas.

Meningiomas are thought to originate from the meningothelial cells of the arachnoid mater and are the most common primary brain tumor in adults. Histologically confirmed meningiomas occur with an incidence of 9.12/100,000 population and account for 39% of all primary brain tumors and 54.5% of all non-malignant brain tumors. Risk factors for meningioma include age 65 years and older, female gender, African-American race, history of exposure to head and neck ionizing radiation, and certain genetic disorders such as neurofibromatosis II. Intracranial meningiomas are the most commonly benign, WHO Grade I neoplasms. Atypical and anaplastic are considered malignant lesions.