Meningioma, also known as arachnoid endothelioma is a common intracranial benign adult. Originated in the meninges and its cellular components derived tissue, such as the dura mater fibroblasts, leptomeningeal cells, but more from the arachnoid endothelial cells, especially some of the formation of arachnoid granules, and is connected with the dura, it is parasagittal meningioma, etc. is the most common occurrence site. Arachnoid cells with the vessel into the brain parenchyma through the choroid plexus stroma and, therefore, meningioma also be found in the brain and ventricles.
Diffusion and transfer of meningiomas:
The incidence of meningioma after glioma, ranking second in intracranial tumors. Foreign literature, intracranial meningioma tumors account for about 13% – 20%, 15% of the domestic literature -18%. Adults are more elderly and fewer children, infants and children less. The 20_60-year-old is more common in all age groups, the peak age of 40 years old. Foreign reports, more men than women, while the proportion of men and women reported similar domestic. Meningioma proliferation and metastasis, according to Beijing Neurosurgical Institute 1595 cases of meningioma and Statistics, male to female ratio of 1.04: 1. Also reported that more women than men. Most tumors are benign, malignant or benign to malignant transformation about 2% -3%. Occurred in children who often malignant tumors tend to. This tumor often single, few cases were multiple, with an incidence approximately 1% -2% of meningioma, occur in female patients, and in the same side of the head, or with other tumors such as acoustic neuroma, metastatic tumor co-exist, sometimes complicated by the glioma.
Generally slow-growing benign meningiomas, and more outside the brain were dilated by the growth, a few showed invasive growth, compression or infiltration of surrounding tissue, the gradual emergence of a variety of signs of increased intracranial pressure. Diffusion and transfer of meningioma, meningioma invasion and infiltration of dura and easy to skull and then to extracranial development, known as invasive meningioma, common in the sagittal sinus or the sphenoid to meningioma. Parasagittal sagittal sinus meningiomas who are often invasive. Yan leaves the Ministry of tumor infiltrating the dura mater and the Yen bone, but also to Yan intramuscular infiltration. End the amount of optic nerve meningioma dark film along the orbital invasion, and infiltration of the lateral rectus muscle, but also the growth along the sinus infiltration, the formation of the skull of local uplift or both are damaged or thinning of the skull, or even infiltration barrier or puncture the skull plate outward growth, the head of local uplift, but also significant expansion of the scalp blood vessels. A small number of meningiomas spread along the cerebrospinal fluid pathways and the transfer of intracranial transplantation, the formation of tumor nodules of varying sizes, scattered in the brain surface, tumor number can be up to several dozen, mostly occurs in post-craniotomy. Histologically, the individual is a benign meningioma meningioma and recurrence, occasionally with extracranial metastasis. More common in malignant supratentorial, cerebral falx or brain at the base, the growth of fast, easy to relapse.Meningioma proliferation and metastasis, in addition to local infiltration, but also along the blood supply and lymphatic metastasis to extracranial, to 1995, more than 80 cases have been reported, the transfer rate of less than 0.01%. Hemangiopericytoma, meningeal sarcoma, atypical and malignant meningiomas and other tumors infiltrating meninges, central nervous system outside the transfer rate of 24%, may be partial sinus invasion or wound caused by surgery, and its more metastatic sites found in lung, liver and cervical lymph nodes.