Juxtaorbital en plaque meningiomas. Report of four cases and review of literature.

摘要: The term meningioma was coined in 1938 by Harvey Cushing to describe a benign tumor arising from the meninges of central nervous system. 9 evolved over years after they were called for many as fungoid tumor, sarcoma, cylindroma, endothelioma, fibroma, and meningothelioma. They have been found arise arachnoid cap or cluster cells close proximity dura mater. are group that most prevalent near collections villi at dural venous sinuses large tributary veins; cribriform plate (olfactory plate); medial regions middle cranial fossae (sphenoid ridge); nerve exit foramina. It is postulated predominantly meningothelial tumors take form cells, whereas more fibrous resemble leptomeningeal stroma. macroscopic appearances meningiomas may be hemispheric, bun-shaped, globular growths firmly attached excavate adjacent neural tissues. Their surfaces usually unevenly nodular, but also smooth. derive thin investing capsule meninges, thus remain extra-axial lesions readily separate brain spinal cord. An important variant en plaque (EPM), which, its name suggests, not greatly raised above level mater notoriously prone invade bone with accompanying hyperostosis. 47 This essentially infiltrates orbit mainly way natural openings, such foramina fissures well perforating blood vessels, which increased number. Of all variety EPM can difficult entity diagnose. Its plaquelike easily visualized on preoperative imaging studies times even following surgical exposure. often associated hyperostosis present up 44% cases neither universal nor specific EPM. 4,8,15 Our review literature demonstrates plain radiographs, tomography, scintigraphy, invasive studies, angiography, CT, recently MR utilized aid diagnosis To best our knowledge, no previous report describes findings fat-suppression gadolinium-enhanced T1-weighted images juxtaorbital Because this lesion mistaken fibro-osseous orbit, dysplasia, we believe contrast, including sequence, essential suggesting differentiating it dysplasia other lesions. Meningiomas responsible almost 13% 19% neoplasm. 17,20 Diagnostic modalities contributed current understanding biologic behavior, clinical presentation, epidemiology meningiomas. Many environmental genetic factors suggested possible contributors pathogenesis Initially, Eisenhardt trauma these tumors; however, several later control failed demonstrate presumed positive correlation meningioma. 1,6 On hand, clear connection between radiation has established. 31 Concurrently, proved irradiated only different biologically multiple, recurred surgery, had malignant atypical histologic features frequently than 19,53 Cytogenetic meningiomas, shown loss DNA chromosome 22, same harboring gene neurofibromatosis type 2. inherited disorder characterized bilateral vestibular schwannomas, gliomas. 45,46,49 Also, papovavirus meningiomas; infection virus demonstrated any neoplastic transformation. 2,44 Hormone-binding assays provided conflicting data regarding presence estrogen progesterone receptors 18 ; described rapid progression neurologic deficits patients who became pregnant. Recent high prevalence an absence receptors. 19,30,40 article presents three surgically EPMs one distinguish CT alone plaque–globular meningioma, reviews