Introduction: A small subset of meningiomas are known to metastasize outside of the central nervous system. This poses a unique clinical challenge for the management of these patients. In this study we describe a case series of patients with extracranial manifestations of meningiomas. We further perform a systematic review of the existing literature to give a global overview on this seemingly rare phenomenon.
Methods: We report six cases of metastatic meningioma managed at our institution over the past 20 years. In addition, we performed a systematic review of the literature going back to the first reported case in 1886. Furthermore, we summarize the features of the cases described in the literature, including time to metastasis and the attempted treatments.
Results: In total, we analyzed 155 relevant reported cases of patients presenting with extracranial manifestations of meningiomas. The most common primary meningioma location was the convexity (54% of cases), and the most common site of metastasis was the lung (61%). Furthermore, we found that males and patients with a higher grade of primary tumor at first biopsy developed extracranial manifestations sooner (p=0.0003 and p=0.0002 respectively). We also found that that the majority of published cases came from high-income countries (84%) whilst only 16% came from lower and middle-income countries.
Conclusion : Metastatic meningiomas pose a serious clinical challenge within modern neurosurgery. As these patients may be missed in clinical practice, awareness and timely identification of these patients is important. In this way, a consensus is needed as to how to correctly screen and manage these patients. The advent of newfound data on the genomic and epigenomic profile of aggressive meningiomas could play a role alongside histopathological analysis. Similarly, a more robust evidence base, in the form of data from multi-center studies, must be found to help inform this consensus.
.jpg "Vratko Himic, BA (Oxon) photo")