Orbital Meningioma Research Articles

Papilla nigra und Melanosis retinae acquisita nach Operation eines Orbitameningeoms - Klinische, histologische und ultrastrukturelle Befunde

Resection of an orbital meningioma in a 53-year-old patient caused an occlusion of the central retinal artery and total ophthalmoplegia. Eight weeks postoperatively rapid development of a black disc was observed with migration of pigment into the juxtapapillary retina. One year later the eye was removed during a radical reoperation. Histological and ultrastructural examination showed that the melanosis of the disc and the retina was apparently due to reactive proliferation of the juxtapapillary pigment epithelium which had migrated into the atrophic tissues of the retina and the disc. The histological differentiation from hamartomatous proliferations of the juxtapapillary pigment epithelium is discussed. The proliferated pigment epithelium cells in this patient resemble those described in epiretinal membranes apart from abundant RER and actin filaments. In the absence of mechanical or inflammatory factors it must be assumed that hypoxia was the stimulus responsible for the proliferation. The presence of fenestrated retinal capillaries in the proliferation zone is described and the significance of this finding is discussed.

Opticociliary Veins in A Primary Optic Nerve Sheath Meningioma

A 59-year-old man developed painless visual loss in his left eye over a one-year period, with rapid progression to blindness over three months. Ocular examination of the left eye revealed proptosis, marked optic disk pallor, dilated retinal veins, and congeries of vessels at the disk margin (opticociliary veins). His right eye was unremarkable. Fluorescein angiography and histopathologic examination confirmed the presence of opticociliary veins communicating between branches of the central retinal vein and the adjacent choroidal vasculature. Primary orbital optic nerve meningioma associated with opticociliary veins was diagnosed.

The radiology of orbital meningioma

During a five-year period three patients with primary and 14 with secondary orbital meningiomas were examined. The appearances seen on plain films, subtraction angiography, venography, scintiscan and EMI scan are described and compared. Plain films were abnormal in 13 of the 17 cases and this was the investigation which most frequently suggested the diagnosis. Arteriographic abnormalities were present within the orbit in 12 of the 16 cases so examined, an actual tumour blush occurring in 6/16. Venography showed evidence of the lesion in 12/14; in two cases it was the only investigation to give positive findings. Abnormality in the adjacent cavernous sinus was demonstrated in 6/13. Scintiscan was negative in the one primary case examined; it showed evidence of the intracranial lesion in the seven secondary cases examined but could not demonstrate intraorbital extension. The orbital lesion would have been demonstrated in all cases without the use of computed tomography but the delineation of the lesion was seen more clearly on the EMI scan in 12/14 than by other methods of investigation. Neither the density of the lesion nor the increase of attenuation after contrast was helpful in suggesting the diagnosis. A combination of plain and contrast radiology with computed tomography is recommended with a view to increasing the diagnostic accuracy and determining the full extent of a lesion. Intracranial investigation is required also, where an orbital space occupying lesion is suspected and orbital examination should be done when an intracranial peri-orbital meningioma is diagnosed. A case history is given to show how the various investigations may complement each other.

Microsurgical anatomy of the orbital apex and principles of transcranial orbital exploration.

Although many problems may present with unilateral proptosis, a careful clinical investigation can narrow the differential diagnosis to those problems which can be treated best by the neurosurgeon. The primary indication for transcranial exploration is when the pathological process is found to involve both the orbit and the cranial cavity as in all cases of optic nerve glioma, orbital meningioma, encephalocele, and some mucoceles, hemangiomas, aneurysmal bone cysts, and ossifying fibromas. Transcranial exploration may also be indicated for some tumors which crowd the orbital apex, such as, neurofibromas and osteomas; tumors in this location can be more widely exposed and safely dealt with by this route. A prime objective in these cases, however, must be preservation of function with a good cosmetic result. It is of equal importance to be aware that many conditions producing exophthalmos can be cured by direct orbital exploration, radiotherapy, or medical management. Malignant orbital tumors should never be exposed to the cranial cavity by transcranial exploration, whereas, radical exenteration may be curative in some carefully studied cases. Accuracy in clinical diagnosis and the proper selection of treatment modality for conditions in the orbit requires a clear understanding of this regional anatomy. I hope that this brief review of the pertinent microsurgical anatomy of the orbital apical region has helped to substantiate a strong neurosurgical claim to all primary optic nerve tumors; and, incidentally, I hope it provides an explanation for why I sent so many other patients back to Dr. Algernon Reese with the recommendation that transcranial surgery did not seem indicated. The success of this attitude may be attested to by the fact that we performed no unnecessary craniotomies nor did we pass by problems which would have best been treated by transcranial orbital exploration.

Orbital meningioma with intraocular invasion in a dog. Histology and ultrastructure.

Vet. Pathol. 14: 521-523 (1977) Orbital Meningioma with Intraocular Invasion in a Dog Histology and Ultrastructure N. BUYUKMIHCI Meningiomas have been reported in a variety of domestic animals [9]. Although most meningiomas have been intracranial, there are several reports of menin- giomas with orbital or ocular involvement or both [l-3, 5-8, 101. A 7-year-old, ovariohysterectomized Scottish Terrier dog had had a “film” over the right eye with gradual increase in prominence of the globe and loss of a menace response for 2 weeks. The dog had had a nonresponsive conjunctivitis of the right eye for 2 months before the “film” developed. The right eye was blind with no direct or consensual pupillary response. The globe was deviated laterally, exophthalmic and fixed in position. The nictitans protruded from the medial canthus. The retina was displaced anteriorly so that parts were in contact with the back of the lens. It could not be determined if the neuroretina was separated from its pigment epithelium or if an intraocular or extraocular mass was causing the anterior displacement. The optic disk was not visible. The diagnosis was a space-occupying lesion in the orbit. After thoracic radiographs showed no evidence of lung disease the right orbit was exenterated. The globe was compressed by firm, moderately vascular tissue that filled the orbit and extended posteriorly to the orbital fissure and optic foramen. The eye with firmly adherent orbital tissue was placed in Zenker’s solution with acetic acid and processed for routine light microscopy. Pieces of the attached mass also were fixed in 10 percent neutral buffered formalin. Formalin-fixed neoplastic tissue was processed for electron microscopy by a rapid method [ll]. Ultrathin sections were stained with uranyl acetate and lead citrate. The dog was re-examined 73 days after surgery. During these 73 days the dog had seemed normal. The exenterated orbit was unremarkable and the left eye normal. Two months later the dog was killed because there was extensive regrowth of the neoplasm. There was destruction of orbital bone (especially zygomatic arch) and invasion of the roof of the pharynx. No invasion of the brain was seen grossly. The lungs contained miliary white nodules. The tissue surrounding the globe looked neoplastic and in some areas had many islands of polygonal cells arranged in swirls; these islands ranged in size from four cells to more than 100 (fig. 1). In other areas, the cells were close together in an indiscriminate manner. The nuclei were generally large and pleomorphic and many contained linear basophilic densities. The abnormal cells gave rise to cartilage, Downloaded from vet.sagepub.com at UNIV CALIFORNIA DAVIS on March 12, 2011

Tumors of the optic nerve.

This is a review of primary and secondary tumors of the optic nerve. The emphasis is an optic nerve gliomas and meningiomas. Optic nerve gliomas are slowly growing astrocytic neoplasms of the anterior visual pathways, the majority of which occur within the first two decades of life, with equal sex incidence in about 1 of 200,000 patients presenting with eye complaints. The incidence is greater in neurofibromatosis. The typical presentation is visual impairment in a verbal pre-school child with optic canal enlargement and optic atrophy. An intraorbital location of the tumor leads to axial, irreducible, non-pulsatile proptosis. An intracranial location may disturb hypothalamic and pituitary function and produce hydrocephalus. Ocular findings may also include limited motility on a mechanical-restrictive basis, a pupillary relative afferent defect, nystagmus, and variable, non-specific visual field defects. Roentgenographic studies may show concentric unilateral enlargement of the optic canal with preservation of a well corticated margin, a fossa under the anterior clinoid process in continuity with the optic canal ('J'-shaped sella), and findings of increased intracranial pressure. On pathologic examination the tumor is a smooth, fusiform, intradural enlargement of the optic nerve. Histologically there is proliferation of elongated (pilocytic) astrocytes in reticulated patterns with intervening microcystic spaces containing mucosubstance and surrounding reactive hyperplasia of the arachnoid. Mitoses are not found. The diagnosis is clinical X-ray studies and brain scan should be performed. The differential diagnosis is that of unilateral proptosis in a child and includes acute ethmoiditis, hyperthyrobidism, craniostenosis, other neoplasms, Hand-Schuller-Christian disease, and orbital hemorrhage due to trauma. Surgical resection is performed in cases with unilateral optic nerve involvement, the surgical approach being determined by tumor location. Bilateral or chiasmal cases are treated with radiotherapy when progression occurs. Malignant optic nerve gliomas and optic nerve hyperplasia are also discussed. Optic nerve meningiomas arise from the nerve sheath and are to be distinguished from orbital meningiomas arising from ectopic arachnoidal cells or those secondarily involving the orbit by extension from adjacent sites. Up to 80% of orbital meningiomas occur in females, in two age peaks, 25% in the first decade, and the rest in the 5th decade. Meningiomas present with visual loss and may produce proptosis, papilledema and/or optic atrophy, retinal striae, opticociliary shunts, limitation of extra-ocular movements, and lid edema, Signs of von Recklinghausen's disease should be sought. X-rays are the mainstay of diagnosis. Orbital meningiomas are composed of cells in sheets or in whorls with some spindle shaped cells. Calcifications are typical. Usually the dura is penetrated and the orbit invaded. Primary orbital meningiomas are locally infiltrating but do not metastasize. Complete local excision en bloc is recommended...

Primary intraorbital meningiomas: a roentgenologic study.

Six cases of primary orbital meningioma, a rare condition, are presented. These tumours provoke bone changes, chiefly increased bone density, in the same way as intracranial meningiomas. Orbitography and orbital venography provide complementary diagnostic information. Arteriography, the most widely used and rewarding investigation, may confirm the presence of an intraorbital lesion by revealing pathological vessels and tumour staining. The most reliable criterion in the preoperative diagnosis of primary intraorbital meningioma is agreement between the appearances of the plain radiographs and those of the angiogram.