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Ординатура / Офтальмология / Английские материалы / Imaging of Orbital and Visual Pathway Pathology_Muller-Forell_2005

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306

W. Müller-Forell and S. Pitz

Fig. 6.174. A 66-year-old woman with complete visual deficit of the right eye. Diagnosis: calcified right sphenoid wing meningioma. Axial CT: Nearly complete calcification of the tumor, arising from the clinoid process with retrograde infiltration of the entire optic nerve sheath through the optic canal into the orbit, and antegrade infiltration of the ipsilateral cavernous sinus. (With permission of Müller-Forell and Lieb 1995)

a

b

c

d

Orbital Pathology

307

a

b

 

Fig. 6.176a–c. A 36-year-old woman with slowly progressing

 

visual deficit of the left eye. Diagnosis: optic nerve sheath

 

meningioma. MRI: a Axial, T1-weighted, contrast-enhanced

 

(FS) view with signal intensity enhancement of the tumor

 

in the posterior orbital apex. Thickening of the rectus mus-

 

cles and dilation of intraorbital vessels (intermittent signal

 

enhancement in the intraconal space) lead to the suspicion

 

of venous congestion. b Corresponding T2-weighted image;

 

comparison with the right optic nerve shows CSF block of

 

the meningeal sheath demonstrated by retrobulbar widening

 

of the subarachnoid space (arrow). c Coronal, T1-weighted,

 

contrast-enhanced (FS) view at the site of the posterior optic

 

canal, visualizing the spread of tumor growth (arrowheads)

 

along the dura of the left clinoid process. Note the normal con-

 

figuration of the contralateral right clinoid process (arrow),

c

normal-sized diameter of both ICA (small arrows). (With per-

mission of Müller-Forell and Lieb 1995b)

Fig. 6.175a–d. A 49-year-old woman with complete loss of vision in the right eye. Diagnosis: optic nerve sheath meningioma with intracranial expansion. MRI: a Axial, T1-weighted, contrast-enhanced view with parallel thickening of the meningeal sheath, compression of the right optic nerve (medial hypointensity), widening of the optic canal, and intracranial infiltration (arrow) with expansion in the direction the optic chiasm. b Parasagittal, T1-weighted, contrast-enhanced (FS) view, demonstrating minor eccentric growth of the meningioma in the apical orbit, and flat extra-axial intracranial meningeal infiltration at the ipsilateral clinoid process (arrows). c Coronal, T1-weighted, contrast-enhanced view also demonstrating concentric compression of the medial part of the optic nerve. d Corresponding coronal view at the level of the optic canal, showing lateral widening of the canal, infiltration of the upper cortex of the clinoid process (arrows), and slight intracranial expansion, all associated with the tumor. Compare with normal configuration of the left side. (With permission of Müller-Forell 1998)

308

W. Müller-Forell and S. Pitz

a

b

c d

Fig. 6.177a–d. A 55-year-old woman with subsequent, slowly progressing loss of vision in the left eye. Diagnosis: eccentric optic nerve sheath meningioma. T1-weighted MRI: a Axial native view with slight proptosis of the left globe and a hyperintense lesion, enclosing the optic nerve. b Corresponding contrast-enhanced image demonstrating nearly homogeneous enhancement of the meningioma, sparing the isointense optic nerve. c Coronal contrast-enhanced view with superior visualization of the mostly supraoptic tumor extension. d Parasagittal contrast-enhanced view with demonstration of the supraoptic growth with neither intracanalicular nor intracranial extension

Fig. 6.178a–f. A 55-year-old woman with slowly progressing axial proptosis of the right eye, examined for possible endocrine orbitopathy. Diagnosis: eccentric meningioma of the optic nerve sheath. MRI: a Axial T2-weighted (FS) view with a well-defined intraconal mass. b Corresponding T1-weighted native view, demonstrating a homogeneous, apparently encapsulated mass. c Corresponding T1-weighted, contrast-enhanced (FS) view with homogeneous, but intermediate enhancement. d Coronal T1weighted native view, where the supraoptic location with optic nerve compression and flattening by the mass is seen. e Corresponding T1-weighted, contrast-enhanced view with relatively low signal enhancement. f Parasagittal, T1-weighted, contrastenhanced (FS) view, demonstrating the intraconal, supraoptic, immediately retrobulbar mass

Orbital Pathology

309

a

b

c

d

e

f

310

ously called mucopolysaccharides) within lysosomes of the cells of most tissues and organs (van der Knaap and Valk 1995; Lake 1997). Although there is some variation among the MPS types, they share a number of characteristic clinical features. In particular, patients with MPS type VI (Maroteaux–Lamy) (Fig. 6.179) clinically resemble, with the exception of normal intelligence (van der Knaap and Valk 1995),patients with MPS type I H (Hurler syndrome); the resemblance of imaging findings is therefore not unexpected. Apparent MRI findings may develop over a period of years and consist of small spot-like lesions in radial orientation to the cortex, caused by deposits of mucopolysaccharides in the perivascular Virchow-Robin spaces of the brain and variable ventricular enlargement (van der Knaap and Valk 1995; Lake 1997; Barkovich 2000). The hyperintensities on T2-weighted images may reflect demyelination and gliosis. Although ocular manifestations are seen in rare cases only (Kenyon 1976), optic nerve compression obviously caused by mucopolysaccharide deposits in the optic nerve sheath (Fig. 6.179) has yet not been described.

6.4.1.3.2 Metastasis

Although ocular involvement of central nervous system lymphoma is known (Akpek et al. 1999; Cassoux et al. 2000), leptomeningeal involvement of systemic or focal extracerebral malignancies in the optic nerve sheath is rare, and seen occasionally with only meningeal manifestation (Fig. 6.180). Patients usually become symptomatic with acute visual disturbances or vision loss (Müller et al. 1990). In HIV-related lymphoma, leptomeningeal involvement represents the most common central nervous system manifestation (Levine 1991), but is rarely observed in the optic nerve sheath. A particularly rare condition endemic to Africa,but sporadically occurring worldwide,is central nervous system and optic nerve sheath involvement in Burkitt lymphoma (Fig. 6.181), a high-grade undifferentiated lymphocytic neoplasm associated with the Epstein-Barr virus (Trese et al. 1980; Rootman et al. 1994; McCartney 1997; Spath-Schwalbe et al. 1999). Optic nerve sheath meningiosis is not restricted to lymphoma, but is also seen in other primary malignancies as, e.g., pancreatic carcinoma (Fig. 6.182). The differential diagnosis for idiopathic optic nerve inflammation in cases of known malignancy might be difficult and should not be based only on imaging criteria, but also on clinical symptoms and follow-up (Figs. 6.183, 6.184).

W. Müller-Forell and S. Pitz

6.4.1.3.3

Cerebral Pseudotumor

Clinical symptoms of cerebral pseudotumor (syn. benign cerebral hypertension) include headache, visual impairment, and bilateral papilledema with or without visual impairment or loss of vision. Primary cerebral pseudotumor due to an intracranial spaceoccupying mass, sinus thrombosis, endocrine metabolic disorders (e.g., hyperparathyroidism, hypothyroidism, or hematological disorders) demand causal therapy (Reul 2001). Idiopathic intracranial hypertension most commonly occurs in middleaged obese women (Weisberg 1985), but children or adolescents may also be affected (Phillips et al. 1998; Cinciripini et al. 1999). Although a large number of associated disorders as, e.g., chronic sinus thrombosis or intracranial dural fistula are known, the etiology remains unknown. However, an increase in CSF production or decreased resorption have been suggested (Donavan et al. 1998; Biondi et al. 1999; Friedman 1999). Clinical findings consist of increased intracranial pressure, but normal CSF composition (Manfre et al. 1995; Phillips et al. 1998; Suzuki et al. 2001). MRI shows normal to small ventricles and in some cases enlarged optic nerve sheaths, combined with a reversal of the optic head (Fig. 6.185) and/or signs of an empty sella. Venous MR-angiography may provide information about venous stenosis, but invasive cerebral venous angiography with manometry precisely defines the amount of venous hypertension (normally about 2–7 mmHg) in the superior sagittal sinus and proximal transverse sinus. The venous pressure increase may be caused by mild to significant narrowing of the distal transverse sinus, mostly of unknown etiology (Fig. 6.186) (King et al. 1995). Conservative therapy consists of medication with acetazolamide and/or prednisolone (Suzuki et al. 2001) in order to reestablish normal intracranial pressure with documented remission (Donovan et al. 1998; Suzuki et al. 2001). In chronic or refractory cases, optic sheath decompression should be performed to prevent a definite optic nerve defect with associated loss of vision (Fig. 6.187) (Horton et al. 1992; Spoor and

McHenry 1995).

6.4.1.3.4

Fibrous Dysplasia

In active fibrous dysplasia, a visual deficit may occur when the process involves the optic canal (Fig. 6.188) (see also Sect. 6.3.2.1.).

(Text continues on p. 318)

Orbital Pathology

311

a

b

c

d

 

Fig.6.179a–e. A 12-year-old girl with myopia persisting for several years,pre-

 

senting for imaging follow-up of mucopolysaccharidosis type VI (Marote-

 

aux–Lamy syndrome). Diagnosis: deposits of mucopolysaccharide in the

 

optic sheath. a Ultrasound of the enlarged optic nerve complex (courtesy of

 

Prof. Schumacher, Kinderklinik, Mainz). MRI (native): b Axial T1-weighted

 

view of the orbit with extreme bilateral thickening of the optic nerve sheath

 

shown to be more pronounced on the left. Both optic nerves are compressed

 

in their orbital course, but exhibit a normal diameter (4 mm) in the optic

 

canal. c Coronal T1-weighted view of the orbit. d Coronal T1-weighted IR

 

view of the brain at the level of the basal ganglia, demonstrating charac-

 

teristic hypointense perivascular spaces (filled with mucopolysaccharides)

 

in the basal ganglia (arrows) and the subcortical vessels (arrowhead), in

 

addition to atrophy of the white matter (star). e Axial T2-weighted FLAIR

 

image at the level of the cella media of the ventricles. Substantial diffuse

 

demyelination of the white matter and diffuse perivascular mucopolysac-

 

charide deposits, isointense with CSF, are most distinctly visualized in the

e

subcortical small vessels, presenting with hypointense signal

312

W. Müller-Forell and S. Pitz

a

b

Fig. 6.180a,b. A 76-year-old man with systemic NH-lymphoma and acute visual disturbance. Diagnosis: meningeal metastasis of NH-lymphoma. CT: a Axial contrast-enhanced image with knotty, bulbar structures in the course of the optic nerve. MRI: b Corresponding axial, T1-weighted, contrast-enhanced (FS) image confirming the diagnosis of meningeal tumor spread with bilateral tumor seeding along the meningeal sheaths in the presence of regular signal and normal formation of both optic nerves. (With permission of Müller-Forell and Lieb 1995)

a

b

 

Fig. 6.181a–c. A 35-year-old man with AIDS and histologically

 

proven meningiosis lymphomatosa (Burkitt lymphoma), pre-

 

senting with acute bilateral, left accentuated loss of vision.

 

Diagnosis: HIV-induced, intraorbital NHL-meningiosis. MRI:

 

a Axial, T1-weighted, contrast-enhanced (FS) image. General

 

enhancement of the left intraconal fat and optic nerve sheath

 

complex is visualized in addition to slight enhancement of the

 

lateral area of the right optic nerve sheath (arrow). b Para-

 

sagittal, T1-weighted, contrast-enhanced (FS) view of the left

 

orbit with enhancement of the optic nerve sheath, the papil-

 

lary region (with papill edema), and the paraoptic fat. c Cor-

 

responding parasagittal view of the right orbit also showing

c

enlargement of the superior ophthalmic vein (compare with

b), apparently caused by venous outflow congestion

Orbital Pathology

313

a

b

 

Fig. 6.182a–c. A 49-year-old man with metastatic spread of pancreatic carci-

 

noma, presenting with bilateral papilledema and acutely decreasing visual

 

loss. Diagnosis: leptomeningeal metastasis. MRI: a Axial, T1-weighted, con-

 

trast-enhanced (FS) view with bilateral enhancement of the subarachnoid

 

space of the optic sheath, best seen at the optic canal. b Coronal, T1-weighted,

 

contrast-enhanced (FS) view where both optic nerves are seen as hypoin-

 

tense structures, surrounded by hyperintense subarachnoid space. c Axial,

c

T1-weighted, contrast-enhanced view of the brain, demonstrating leptomen-

ingeal tumor infiltration at the depth of the left frontal sulci (arrows)

314

W. Müller-Forell and S. Pitz

a

b

c

d

Fig. 6.183a–d. A 38-year-old woman with acute loss of vision in the left eye and a history of breast carcinoma. Cortisone therapy was successful, and nothing abnormal was detected on follow-up after 24 months; differential diagnosis of meningeal metastasis of the primary tumor is unlikely. Diagnosis: idiopathic inflammation of the left optic nerve. MRI: a Axial T1-weighted native view. b Corresponding contrast-enhanced (FS) image with irregular enhancement along the left optic nerve sheath complex. c Coronal T2-weighted view where the left optic nerve exhibits significant signal enhancement. d Corresponding T1-weighted, contrast-enhanced (FS) view with significant T1-time shortening of the left optic nerve

Orbital Pathology

315

b

a

Fig. 6.184a,b. A 75-year-old woman with symptomatology of right-sided retrobulbar neuritis and a history of breast cancer. Diagnosis: idiopathic inflammation of the optic nerve sheath. MRI: a Axial, T1-weighted, contrast-enhanced (FS) view showing enhancement of the right optic nerve sheath. b Coronal view confirming additional infiltration of the paraoptic orbital fat (white star) suspected from another axial view (not shown). Differential diagnosis of meningeal metastasis was excluded on follow-up, which showed complete remission of the clinical symptoms after high-dose corticosteroid treatment, confirmed by neuroradiological imaging (not shown)

a

b

Fig. 6.185a,b. A 24-year-old woman with chronic papilledema. Diagnosis: cerebral pseudotumor. MRI: a Axial T2-weighted view demonstrating the impression of the papilla by the optic nerves. b Coronal T2-weighted view with enlargement of the subarachnoid space of the intraorbital optic nerve sheath

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