Ординатура / Офтальмология / Английские материалы / Tumors of the Eye and Ocular Adnexa_Char_2001

360 TUMORS OF THE EYE AND OCULAR ADNEXA

A B

Figure 18–10. Comparison of T1-weighted MRI scan (A) and T1 fat saturation gadolinium scan (B) in the same case.

portion of the nerve through a lateral orbitotomy, leaving an intact eye (Figure 18–12).

Seven cases that have been classified by the reporting authors as optic nerve sheath meningiomas have been resected, with improved vision after surgery.37 Probably some of these tumors were meningiomas that did not involve the nerve sheath, although one or two may have been very small lesions picked up just posterior to the globe.14,19,37,49,50 In our experience, we have not seen a patient with an optic nerve sheath meningioma that could be removed with the preservation of good vision. Virtually all patients who have been operated on with optic nerve sheath tumors have had marked reduction of visual acuity.37

Patients with nonoptic nerve sheath meningiomas generally have a better visual outcome, and neither group of orbital meningioma patients has significant tumor-related mortality. Less than 2 percent of optic nerve sheath meningioma patients have

died as a direct result of tumor, but a number of studies have demonstrated a higher tumor-related mortality in children.12,51

We have had good results with sphenoid wingorbital meningiomas, using orbital resection and a combination of neurologic and ophthalmologic surgeons, with the addition of postoperative radiation.52,53

OTHER OPTIC NERVE TUMORS AND

SIMULATING LESIONS

As previously mentioned, a number of lymphoid tumors can involve the optic nerve either primarily or secondarily. A systemic lymphoma with unknown CNS and optic nerve involvement is shown in Figure 18–1. This is one of the few areas in which orbital ultrasonography may be both as accurate as either CT or MRI and more cost effective at differentiating inflammation from an optic nerve tumor. Often, a “T sign” is produced on B-scan as a result of fluid in the sub-Tenon’s space (Figure 26–23). Almost all these patients have other findings of lymphoid tumor in the orbit, often including a diffuse mass surrounding the nerve. Occasionally, the idiopathic benign lymphoid lesions can be difficult to differentiate from other inflammatory lesions as an isolated retrobulbar sarcoid inflammatory process.54,55 The MRI findings in such cases are not always diagnostic.5,56 An axial CT scan demonstrating biopsy-proven sarcoidosis surrounding the optic nerve is shown in Figure 18–2. The patient also had an elevated serum angiotensin converting enzyme

(ACE) level and a positive limited gallium scan (see Figure 20–14) but was otherwise asymptomatic.

An idiopathic optic neuritis usually produces a smooth, diffuse enlargement of the nerve; in multiple sclerosis, MRI can often detect nonsymptomatic CNS plaques.57,58

An asymmetric enlarged inferior rectus muscle in thyroid eye disease can simulate an optic nerve tumor (Figure 18–13). While this was a problem with the first generation of CT scans, image reformation almost eliminated this misdiagnosis.59 More recently, however, this problem has resurfaced. We have seen two cases in which axial MRI scans were thought to represent optic nerve tumors.

Metastases confined to the optic nerve are uncom- mon.29,60–63 We have rarely observed these in association with either breast or lung carcinoma. Usually, the intraocular portion of the nerve is involved, and acute anterior ischemic optic neuropathy must be considered in the differential diagnosis. Occasionally, with prostate metastases to the area of the bony canal, compression neuropathy occurs. These lesions will often respond to corticosteroids and radiation. Optic nerve involvement by a peripapillary uveal melanoma or a retinoblastoma is readily apparent on fundus examination and has been observed much more frequently than distant metastases to this site.61

A number of rarer optic nerve tumors can occur in adults. Hoyt described malignant optic nerve

Figure 18–13. An enlarged inferior rectus muscle simulating an optic nerve tumor on axial CT in a patient referred for an optic nerve tumor. Reformatted images demonstrated the true nature of the lesion.

gliomas with very high tumor-related mortality.64 Paraganglioma can mimic an optic nerve sheath meningioma.65 Usually, paragangliomas arise in the carotid body; and much less commonly, they can involve the larynx or sinuses. Approximately 30 cases of paragangliomas in the orbit have been described. About 40 percent of patients with orbital disease have died as a result of the tumor.65,66 Amputation neuromas can also occur, and several cases have been reported after enucleation or severance of various intraorbital nerves.67 Other rare tumors in the realm of the neuro-ophthalmologist include hemangioblastoma of the optic nerve, choristomas and arachnoid cysts of the optic nerve, and arteriovenous malformation.57,68–70 The latter entity, also known as Wyburn-Mason syndrome, often has a typical fundus pattern and is discussed under retinal tumors (see Chapter 11).

REFERENCES

1.Dutton JJ, Anderson RL. Idiopathic inflammatory perioptic neuritis simulating optic nerve sheath meningioma. Am J Ophthalmol 1985;100:424–30.

2.Li WW, Pettit TH, Zakka KA. Intraocular invasion by papillary squamous cell carcinoma of the conjunctiva. Am J Ophthalmol 1980;90:697–701.

3.Bullock JD, Yawes B, Kelly M, McDonald LW. NonHodgkin’s lymphoma involving the optic nerve. Ann Ophthalmol 1979;11:1477–80.

4.Zappia RJ, Smith ME, Gay AJ. Prostatic carcinoma metastatic to optic nerve and choroid arch. Ophthalmology 1972;87:642–5.

5.Ing EB, Garrity JA, Cross SA, Ebersold MJ. Sarcoid masquerading as optic nerve sheath meningioma. Mayo Clin Proc 1997;72:38–43.

6.Leventer DB, Merriam JC, Defendini R, et al. Enterogenous cyst of the orbital apex and superior orbital fissure. Ophthalmology 1994;101:1614–21.

7.Johnson TE, Weatherhead RG, Nasr AM, Siqueria EB. Ectopic (extradural) meningioma of the orbit: a report of two cases in children. J Pediatr Ophthalmol Strabismus 1993;30:43–7.

8.Longstreth WT, Dennis LK, McGuire VM, et al. Epidemiology of intracranial meningioma. Cancer 1993;72:639–48.

9.Craig WMcK, Gogela LJ. Intraorbital meningiomas: a clinicopathologic study. Am J Ophthalmol 1949;32: 1663–80.

10.Henderson JW. Orbital tumors, 3rd ed. New York, NY: Raven Press; 1994.

362 TUMORS OF THE EYE AND OCULAR ADNEXA

11.Wright JE. Primary optic nerve meningiomas: clinical presentation and management. Trans Am Acad Ophthalmol Otolaryngol 1977;83:617–25.

12.Karp LA, Zimmerman LE, Borit A, et al. Primary intraorbital meningiomas. Arch Ophthalmol 1974; 91:24–8.

13.Reese AB. Expanding lesions of the orbit. Trans Ophthalmol Soc UK 1971;91:85–104.

14.Ueki K, Wen-Bin C, Narita Y, et al. Tight association of loss of merlin expression with loss of heterozygosity at chromosome 22q in sporadic meningiomas. Cancer Res 1999;59:5995–8.

15.Tse JY, Ng HK, Lau KM, et al. Loss of heterozygosity of chromosome 14q in lowand high-grade meningiomas. Hum Pathol 1997;28:779–85.

16.Leone PE, Bello MJ, de Campos JM, et al. NF2 gene mutations and allelic status of 1p, 14q and 22q in sporadic meningiomas. Oncogene 1999;1:2231–9.

17.Wolter JR, Benz SC. Ectopic meningioma of the superior orbital rim. Arch Ophthalmol 1976;94:1920–2.

18.Tan KK, Lim SM. Primary extradural intraorbital meningioma in a Chinese girl. Br J Ophthalmol 1965;49:377–80.

19.Macmichael IM, Cullen JF. Primary intraorbital meningioma. Br J Ophthalmol 1969;53:169–73.

20.Cooling RJ, Wright JE. Arachnoid hyperplasia in optic nerve glioma: confusion with orbital meningioma. Br J Ophthalmol 1979;63:596–9.

21.Hart WM Jr, Burde RM, Klingele TG, Perlmutter JC. Bilateral optic nerve sheath meningiomas. Arch Ophthalmol 1980;98:149–51.

22.Liano H, Garcia-Alix C, Lousa M, et al. Bilateral optic nerve meningioma: case report. Eur Neurol 1982; 21:102–6.

23.Trobe JD, Glaser JS, Post JD, Page LK. Bilateral optic canal meningiomas: a case report. Neurosurgery 1978;3:68–74.

24.Kennerdell J, Maroon J. Intracanalicular meningioma with chronic optic disc edema. Ann Ophthalmol 1975;7:507–12.

25.Als E. Intraorbital meningiomas encasing the optic nerve: a report of two cases. Acta Ophthalmol 1969; 47:900.

26.Hannesson OB. Primary meningioma of the orbit invading the choroid: report of a case. Acta Ophthalmol 1971;49:627.

27.Walsh FB. Selected optic neuropathies. Japan J Ophthalmol 1974;18:1.

28.Mandelcorn MS, Shea M. Primary orbital perioptic meningioma. Can J Ophthalmol 1971;6:293.

29.Sanders M, Falconer MA. Optic nerve compression by an intracanalicular meningioma. Br J Ophthalmol 1964;48:13.

30.Henderson JW, Campbell RJ. Primary intraorbital

meningioma with intraocular extension. Mayo Clin Proc 1977;52:504–8.

31.Imes RK, Schatz H, Hoyt WF, et al. Evolution of opticociliary veins in optic nerve sheath meningioma. Arch Ophthalmol 1985;103:59–60.

32.Backhouse O, Simmons I, Frank A, Cassels-Brown A. Optic nerve breast metastasis mimicking meningioma. Aust NZJ Ophthalmol 1998;26:247–9.

33.Jakobiec FA, Depot MJ, Kennerdell JS, et al. Combined clinical and computed tomographic diagnosis of orbital glioma and meningioma. Ophthalmology 1984;91:137–55.

34.Rotfus WE, Curtin HD, Slamovits TL, Kennerdell JS. Optic nerve sheath enlargement. Radiology 1984; 150:409–15.

35.Johns TT, Citrin CM, Black J, Sherman JL. CT evaluation of perineural orbital lesions: evaluation of the “tram-track” sign. Am J Neuroradiol 1984;5:587–90.

36.Peyster RG, Hoover ED, Hershey BL, Haskin ME. High resolution CT of lesions of the optic nerve. AJR Am J Roentgenol 1983;140:869–74.

37.Dutton JJ. Optic nerve sheath meningiomas. Surv Ophthalmol 1992;37:167–83.

38.Sibony PA, Kennerdell JS, Slamovits TL, et al. Intrapapillary refractile bodies in optic nerve sheath meningioma. Arch Ophthalmol 1985;103:383–5.

39.Daniels DL, Herfkins R, Gager WE, et al. Magnetic resonance imaging of the optic nerves and chiasm. Radiology 1984;152:79–83.

40.Alper MG, Sherman JL. Gadolinium enhanced magnetic resonance imaging in the diagnosis of anterior visual pathway meningiomas. Trans Am Ophthalmol Soc 1989;87:384–419.

41.Lindblom B, Truwit CL, Hoyt WF. Optic nerve sheath meningioma. Ophthalmology 1992;99:560–6.

42.Nadalo LA, Easterbrook J, McArdle CB, et al. The neuroradiology of visual disturbances. Neurol Clin 1991;9:1–33.

43.Kennerdell JS, Dubois PJ, Dekkeer A, Johnson BL. CT-guided fine needle aspiration biopsy of orbital optic nerve tumors. Ophthalmology 1980;87:491–6.

44.Cristallini EG, Bolis GB, Ottaviano P. Fine needle aspiration biopsy of orbital meningioma. Acta Cytologica 1990;34:236–8.

45.Barbaro NM, Gutin PH, Wilson CB, et al. Radiation therapy in the treatment of partially resected meningiomas. Neurosurgery 1987;20:5625–8.

46.Newmann SA. Meningiomas: a quest for the optimum therapy. J Neurosurg 1994;80:191–4.

47.Rosenberg LF, Miller NR. Visual results after microsurgical removal of meningiomas involving the anterior visual system. Arch Ophthalmol 1984;102: 1019–23.

48.Pless M, Lessell S. Spontaneous visual improvement in

orbital apex tumors. Arch Ophthalmol 1996;114: 704–6.

49.Mark LE, Kennerdell JS, Maroon JC, et al. Microsurgical removal of a primary intraorbital meningioma. Am J Ophthalmol 1978;86:704–9.

50.Kennerdell JS, Maroon JC, Malton M, Warren FA. The management of optic nerve sheath meningiomas. Am J Ophthalmol 1988;106:450–7.

51.Alper MG. Management of primary optic nerve meningioma: current status-therapy in controversy. J Clin Neuro-ophthalmol 1981;1:101–17.

52.Goldsmith BJ, Rosenthal SA, Wara WM, Larson DA. Optic neuropathy after radiation of meningioma. Radiology 1992;185:71.

53.Goldsmith BJ, Wara WM, Wilson CB, Larson DA. Postoperative irradiation of sub-totally receptive meningiomas: a retrospective analysis of 140 patients treated from 1967–1990. J Neurosurg 1994;80: 195–201.

54.Kelley JS, Green WR. Sarcoidosis involving the optic nerve head. Arch Ophthalmol 1973;89:486–8.

55.Som PM, Sacher M, Weitzner I Jr, et al. Sarcoidosis of the optic nerve. J Comput Assist Tomogr 1982;6: 614–6.

56.Carmody RF, Mafee MF, Goodwin JA, et al. Orbital and optic pathway sarcoidosis: MR findings. Am J Neuroradial 1994;15:775–83.

57.Howard CW, Osher RH, Tomsak RL. Computed tomographic features in optic neuritis. Am J Ophthalmol 1980;89:699–702.

58.Jacobs L, Kinkel PR, Kinkel WR. Silent brain lesions in patients with isolated idiopathic optic neuritis: a clinical and nuclear magnetic resonance imaging study. Arch Neurol 1986;43:452–5.

59.Char DH, Norman D. The use of computed tomogra-

phy and ultrasonography in the evaluation of orbital masses. Surv Ophthalmol 1982;27:49–63.

60.Arnold AC, Hepler RS, Badr MA, et al. Metastasis of adenocarcinoma of the lung to optic nerve sheath meningioma. Arch Ophthalmol 1995;113:346–51.

61.Christmas NJ, Mead MD, Richardson EP, Albert DM. Secondary optic nerve tumors. Surv Ophthalmol 1991;36:196–206.

62.Sung JU, Lam BL, Curtin VT, Tse DT. Metastatic gastric carcinoma to the optic nerve. Arch Ophthalmol 1998;116:692–3.

63.Kattah JC, Chrousos GC, Roberts J, et al. Metastatic prostate cancer of the optic canal. Ophthalmology 1993;100:1711–5.

64.Hoyt WF, Meshel LG, Lessell S, et al. Malignant optic glioma of adulthood. Brain 1973;96:121–32

65.Amemiya T, Kadoya M. Paraganglioma in the orbit. J Cancer Res Clin Oncol 1980;96:169–79.

66.Bednar MM, Trainer TD, Aitken PA, et al. Orbital paraganglioma: case report and review of the literature. Br J Ophthalmol 1992;76:183–5.

67.Messmer EP, Camara J, Boniuk M, Font RL. Amputation neuroma of the orbit: report of two cases and review of the literature. Ophthalmology 1984;91: 1420–3.

68.Zimmerman LE, Arkfeld DL, Schenken JB, et al. A rare choristoma of the optic nerve and chiasm. Arch Ophthalmol 1983;101:766–70.

69.Lauten GJ, Eatherly JB, Ramirez A. Hemangioblastoma of the optic nerve: radiographic and pathologic features. Am J Neuroradiol 1981;2:96–9.

70.Char DH, Unsold R. Ocular and orbital pathology: clinical aspects. In: Newton TH, Bilaniuk LT, editors. Radiology of the eye and orbit. Raven Press; 1990 p. 9–1 –9.64.

The extraconal space is defined as the extraocular muscles and the orbital volume outside the muscle cone. Intraconal tumors usually produce axial proptosis; extraconal tumors, depending on their location, more often displace the globe downward, laterally, medially, or upward. The duration of symptoms, history of systemic illness, tumor location, computed tomography (CT) or magnetic resonance imaging (MRI) are extremely important parameters in establishing a differential diagnosis for a patient.

Histologically identical tumors can occur in multiple or different orbital areas. We have arbitrarily divided our discussion of extraconal orbital tumors into those that most commonly involve the extraocular muscles, orbital bone, lacrimal fossa, and adjacent areas. Orbital lymphoid lesions are the most frequent extraconal adult tumors. In general, medial orbital tumors are frequently caused by sinus-related lesions. Lymphoid or epithelial lesions most commonly involve the lacrimal gland. Superior masses most frequently are either lymphoid/pseudotumors or metastases. Inferior orbital tumors are relatively uncommon.

EXTRAOCULAR MUSCLES

Extraocular muscle involvement is most often due to idiopathic inflammation, thyroid myopathy, or metastases, although a number of other entities can produce extraocular muscle enlargement (Table 19–1).1

An accurate history is crucial to establishing the correct diagnosis in these cases; the CT or MRI pattern is often characteristic for a given entity.2,3 As discussed in the chapter on lymphoid lesions, idiopathic orbital myositis is most common in patients in the

first three decades of life.4–6 The clinical presentation is the rapid onset of discomfort and/or pain on extraocular movement. Usually, a single, unilateral muscle is involved. Limitation of movement is most common in the field of action of the involved muscle. Most commonly, single or multiple recti muscles are involved, although in about 20 percent of cases, the oblique muscles are infiltrated by lymphocytes.7,8 Figure 19–1 shows a typical orbital MRI pattern of an idiopathic myositis that involves the entire muscle, including the tendon. Patients show a dramatic response to 80 mg of oral prednisone given for 7 to 10 days; in about 80 percent of cases, there is a complete resolution of symptoms with no recurrence.

Table 19–1. DIFFERENTIAL DIAGNOSIS OF ENLARGED

EXTRAOCULAR MUSCLES: CT AND MRI SCANS

Graves’ disease

Vascular (carotid-cavernous fistula or arteriovenous malformation): enlarged superior ophthalmic vein Acute orbital myositis: irregular muscle enlargement

Orbital pseudotumor

Malignant lymphoid tumor Metastatic breast carcinoma Metastatic cutaneous melanoma Metastatic neuroblastoma Metastatic lung carcinoma Metastatic carcinoid

Metastatic pancreatic carcinoma Metastatic seminoma

Leukemia Cysticercosis

Wegener’s granulomatosis Eosinophilic granuloma of soft tissue Angioma

Rhabdomyosarcoma Acromegaly

Malignant nonchromaffin paraganglioma Mesodermal dysplasia

Trichinosis

(From Char1, with permission)

Figure 19–1. CT pattern of idiopathic orbital myositis. The entire length of the muscle and tendon is involved, in contrast to thyroid myopathy, which spares the tendon.

Extraocular muscle lymphoid lesions are less common in older patients, and there are often fewer symptoms in these cases. We have managed a number of patients, in their fifth through eighth decades of life, who presented with either benign or malignant lymphoid lesions involving the recti, oblique, or levator muscles and who had minimal evidence of muscle dysfunction (Figure 19–2).9 Probably, the differences in clinical pattern between older and younger patient groups is partly due to different patterns of inflammatory cells. Younger patients with acutely symptomatic idiopathic orbital myositis have more acute inflammatory cells than are found in a neoplastic lymphocytic infiltration seen in older, relatively less symptomatic patients. Occasionally, lymphomas that involve the extraocular muscle can be acutely symptomatic. Figure 19–3 shows a lymphoma in the superior oblique muscle in a patient who presented with pain and diplopia. The patient developed nonophthalmic lymphoma and was treated with chemotherapy.

In approximately 80 percent of patients with thyroid orbitopathy, there is a history of systemic Graves’ disease. Figure 19–4 shows a patient who had consulted three excellent ophthalmologists about a proptosis of uncertain etiology. Unfortunately, the obvious swelling of the neck had not been noted.

Although bilateral proptosis with scleral show is almost pathognomonic for thyroid-related eye dis-

A

B

Figure 19–2. A, Monoclonal lymphoid lesion involving the superior rectus and levator. Direct parasagittal T1-weighted MRI scan. B, Direct coronal T1-weighted MRI scan; note enlargement of the left superior rectus and levator muscles.

366 TUMORS OF THE EYE AND OCULAR ADNEXA

A sequential systemic laboratory evaluation is indicated for a patient with proptosis who has enlarged extraocular muscles but no orbital mass (Table 19–2). It is often difficult to clinically differentiate idiopathic myositis from thyroid myopathy (see chapter on orbital lymphoid tumors). Figure 19–5 shows typical thyroid extraocular muscle involvement on axial CT. The tendon is spared, and there is enlargement of only the extraocular muscle belly. Often, patients with thyroid orbitopathy have

A

Figure 19–4. Enlarged thyroid gland in a patient who presented with orbitopathy.

asymmetric disease. They may have unilateral involvement of only a single muscle, which gives a pattern on either direct axial MRI or CT, without computer re-formation, that can simulate an apical orbital tumor (Figure 19–6). Thyroid-related orbitopathy can be ruled out if an orbital mass is present on imaging studies. Rarely, however, two processes can be concurrently present. Dabbs and Kline presented a patient who had bilateral optic nerve sheath meningiomas and thyroid ophthalmopathy.10 Patients with myopathy, no mass, and negative thyroid tests may have “euthyroid ophthalmopathy” and up to 40 percent of those patients will develop thyroid disease on long-term follow-up.2 If an extensive experimental laboratory evaluation is

B

Figure 19–3. A, Lymphoma involving the superior oblique muscle. Direct T1-weighted axial MRI scan. B, Direct T1-weighted parasagittal MRI scan. The patient later developed widespread disease.

Table 19–2. SEQUENTIAL LABORATORY EVALUATION

TO DIAGNOSE THYROID ORBITOPATHY

1.Serum thyroid stimulating hormone (TSH), thyrotropin

2.Serum thyroid stimulating immunoglobulin antibodies (TSI)

3.Antimicrosomal and antithyroglobulin antibodies

Figure 19–5. Axial CT scan of an enlarged extraocular muscle in thyroid orbitopathy with sparing of the tendons.

performed on all these patients, thyroid abnormalities are detectable, although with routine laboratory studies, this group still has a 10 percent false-nega- tive rate.1,6

In thyroid ophthalmopathy, fibrosis and inflammation of the muscle usually produce restriction, with limitation of movement away from a muscle’s field of action. Idiopathic myositis patients often have diffuse episcleral and scleral vascular engorgement. Thyroid eye disease, in contrast to idiopathic myositis, often has discrete dilated vessels over the insertions of the extraocular muscles (Figure 19–7). A number of less common causes of enlarged extraocular muscles are reviewed in reference 1.

B

Figures 19–7. A and B, Dilated vessels over the insertion of the extraocular muscles in thyroid orbitopathy. (From Char,1 with permission)

All patients but one with metastatic tumors to the extraocular muscles whom the author has managed presented with a known history of widespread disease.11,12 In metastatic tumors to the extraocular muscles, three clinical and imaging patterns are common.

368 TUMORS OF THE EYE AND OCULAR ADNEXA

First, a single muscle may be involved by metastasis. Figure 19–8 shows an adenocarcinoma metastatic to the superior muscle complex; a similar presentation in the medial rectus is seen in Figure 25–4. Second, there can be diffuse involvement of the extraocular muscles by a metastatic tumor (Figure 19–9). While this pattern can occasionally simulate thyroid orbitopathy, muscle enlargement is more uniform in thyroid orbitopathy and more patchy in metastases. Third, metastases can involve both the extraocular muscle and contiguous structures (Figure 19–10); this pattern allows easy differentiation of metastases from either idiopathic myositis or thyroid myopathy.

Other processes, such as a reaction to a foreign body, can simulate orbital myositis. The CT scan and fine-needle biopsy shown in Figure 19–11A and B were produced by a foreign body that responded to intralesional steroids.

Occasionally, other imaging findings may be important in ascertaining the correct etiology of extraocular muscle enlargement. Figures 19–12A and B show axial CT scans of a patient managed elsewhere with high-dose steroids for thyroid orbitopathy. An axial CT scan of the superior orbit demonstrates asymmetric enlargement of the superior ophthalmic vein. This pattern, in combination with arterialization of the conjunctiva (Figure 19–12C), is virtually pathognomonic for either a dural shunt or a carotid cavernous fistula.16 Figure 19–13 shows a coronal CT scan of an alveolar soft

Figure 19–9. Metastases involving extraocular muscles and simulating apical compressive thyroid optic neuropathy. Note that the muscles are not as regularly enlarged as in thyroid myopathy.

Figure 19–10. Metastasis to extraocular muscles and contiguous orbit on axial CT scan.

A

B

Figure 19–11. A, Axial CT scan with coronal re-formation demonstrates unsuspected foreign body mass involving medial rectus. B, Fine-needle biopsy shows polarizing foreign body; other areas of slide demonstrated numerous inflammatory cells. Symptoms resolved after periocular injection of steroids at the time of biopsy.

B

C

Figure 19–12. A, Axial CT scan shows unilateral enlargement of extraocular muscles in a pattern consistent with thyroid orbitopathy. B, Axial CT scan of the superior orbit shows marked asymmetry in the superior ophthalmic vein due to carotid-cavernous fistula. C, Clinical photograph shows arterialization of the conjunctival vessels that is almost pathognomonic for a carotid-cavernous or dural fistula.

Figure 19–14. Enlargement of superficial vessels overlying an alveolar soft part sarcoma.

such as intramuscular dermoid cysts, have been reported.17 Hakim and colleagues have reported three cases of spontaneous intramuscle hemorrhage that simulates the appearance of thyroid myopathy.18 In approximately 40 to 50 percent of patients with orbital cysticercosis, there is a cystic enlargement of an extraocular muscle.19,20

REFERENCES

1.Char DH. Thyroid eye disease, 3rd ed. Boston, MA: Butterworth-Heinemann Inc.; 1997.

2.Char DH, Norman D. The use of computed tomography and ultrasonography in the evaluation of orbital masses. Surv Ophthalmology 1982;27:49–63.

3.Char DH, Unsold R. Ocular and orbital pathology: clinical aspects. In: Newton TH, Hasso AN, Killon WP, editors. Modern neuroradiology, Vol 3: Computed tomography of the head and neck. New York, NY: Clavadel Press; 1988.

4.Slavin ML, Glaser JS. Idiopathic orbital myositis: report of six cases. Arch Ophthalmol 1982;100:1261–5.

5.Weinstein GS, Dresner SC, Slamovits TL, Kennerdell JS. Acute and subacute orbital myositis. Am J Ophthalmol 1983;96:209–17.