Meningioma
Meningiomas are leptomeningeal neoplasms thought to originate from arachnoid membranes that form the cranial and spinal meninges 1).
Written with Louise Eisenhardt and published in 1938, Meningiomas is a monograph of incredible description and detail. The meticulous categorization of meningiomas, their presentation, clinical outcome, and surgical therapies are even further supplemented by Cushing's personal commentary, questions, and recollections. Cushing's genius was evident in his ability not only to make insightful clinical observations, but also to synthesize these ideas within the neurosurgical context of his era. As he says in Meningiomas, “Thus the pathological curiosity of one day becomes in its proper time a commonplace… most of which are one and the same disorder–had, for their interpretation, to await the advent of the Neurosurgeon 2).
Epidemiology
Classification
see Meningioma classification.
Etiology
see Meningioma etiology.
Pathogenesis
Clinical features
The most common clinical features of meningiomas are neurological deficits.
Symptoms depend on the location of the tumor, and some specific locations are associated with well-described symptom complexes.
Seizures may occur with supratentorial meningiomas as a result of irritation of the cerebral cortex.
Asymptomatic meningiomas
Diagnosis
see Meningioma Diagnosis.
Differential diagnosis
see Meningioma differential diagnosis.
Treatment
see Meningioma treatment.
Outcome
see Meningioma outcome.
Recurrence
Simpson grading system
The Top 100 Most Cited Articles
In November 2016, Almutairi et al. performed a title-specific search of the Scopus database using “Meningioma” as the search query term without publication date restrictions. The top 100 most cited articles were obtained and reviewed.
The top 100 most cited articles received a mean 198 citations per paper. Publication dates ranged from 1953 to 2013; most articles were published between 1994 and 2003, with 50 articles published during that period. NEUROSURGERY published the greatest number of top cited articles (22 of 100). The most frequent study categories were laboratorial studies (31 of 100) and natural history studies (28 of 100). Non-operative management studies were twice as common as operative management studies in the top cited articles. Neurosurgery as a specialty contributed to 50% of the top 100 list. The most contributing institute was the Mayo Clinic (11%); the majority of the top cited articles originated in the United States (53%).
They identified the top 100 most-cited articles on meningioma that may be considered significant and impactful works, as well as the most noteworthy. Additionally, they recognized the historical development and advances in meningioma research, and the important contributions of various authors, specialty fields, and countries. A large proportion of the most cited articles were written by authors other than neurosurgeons, and many of these articles were published in non-neurosurgery journals 3).
Case series
2016
Gousias et al., reviewed their institutional experience with a policy based on maximal safe resections for meningiomas, and they analyzed the impact of the degree of resection on functional outcome and progression free survival (PFS).
They retrospectively analyzed 901 consecutive patients with primary meningiomas (716 WHO Grade I, 174 Grade II, and 11 Grade III) who underwent resections at the University Hospital of Bonn between 1996 and 2008. Clinical and treatment parameters as well as tumor characteristics were analyzed using standard statistical methods.
The median follow-up was 62 months. PFS rates at 5 and 10 years were 92.6% and 86.0%, respectively. Younger age, higher preoperative Karnofsky Performance Scale (KPS) score, and convexity tumor location, but not the degree of resection, were identified as independent predictors of a good functional outcome (defined as KPS Score 90-100). Independent predictors of PFS were degree of resection (Simpson Grade I vs II vs III vs IV), MIB-1 index (< 5% vs 5%-10% vs >10%), histological grade (WHO I vs II vs III), tumor size (≤ 6 vs > 6 cm), tumor multiplicity, and location. A Simpson Grade II rather than Grade I resection more than doubled the risk of recurrence at 10 years in the overall series (18.8% vs 8.5%). The impact of aggressive resections was much stronger in higher grade meningiomas.
A policy of maximal safe resections for meningiomas prolongs PFS and is not associated with increased morbidity 4).