Ординатура / Офтальмология / Английские материалы / Orbital Tumors Diagnosis and Treatment_Karcioglu_2005

FIGURE 22.10. (A) Axial CT image showing a large, secondary orbital tumor originating from the choroidal melanoma within a phthisic eye. Note the posterior scleral calcification in the globe. The orbital tumor occupies the entire socket, extending into the ethmoidal sinus and the apex. (B) A prephthisic left globe shows a dome-shaped posterior density continuous through the sclera into the anterior orbit. The lesion could not be visualized because of a densely opaque cornea, and the clinical diagnosis was a choroidal melanoma extending into the orbit. However, histopathologic examination revealed a partially organized hematoma

within the globe and the orbit. (C) T1-weighted, contrast-en- hanced coronal MR image demonstrating a homogeneous, irregular choroidal melanoma revealing a signal isointense with the cerebral cortex. The extensive infiltration of the tumor into the orbital fat, medial, and inferior orbital walls and into the maxillary sinus is clearly seen. (D) A known diffuse flat choroidal melanoma on the lateral aspect of the globe extending into the lateral periocular and anterior orbital soft tissues. The lateral rectus muscle is also thickened with secondary choroidal melanoma involvement (arrowhead).

noma originating from the choroid can be treated with brachytherapy with some success when the extraocular extension is less than 3 mm thick (Figure 22.11).43 When the melanoma nodule is greater than 3 mm in diameter, enucleation is performed to remove the mel-

FIGURE 22.11. Treatment of extraocular melanoma with I-125 brachytherapy plaque.

anoma nodule encased by normal-appearing orbital fat.54 In larger and more invasive tumors, total or partial exenteration is done (see Chapter 31).55–57 In general, extraocular extension, particularly orbital extension, is a poor prognostic indicator, with a 5-year mortality rate reported to range from 45 to 65%.37

References

1.Shields JA, Bakewell B, Augsberger JJ, et al. Classification and incidence of space-occupying lesions in the orbit: survey of 645 biopsies. Arch Ophthalmol 1984;120:1606–1611.

2.Henderson JW, Campbell RJ, Farrow GM, Garrity JA. Orbital Tumors. New York: Raven Press; 1994:43–52.

3.Günalp I, Gündüz K. Biopsy-proven orbital lesions in Turkey. A survey of 1092 cases over 30 years. Orbit 1994;13:67–79.

4.Seregard S, Sahlin S. Panorama of orbital space-occupying lesions. The 24-year experience of a referral center. Acta Ophthalmol Scand 1999;77:91–98.

5.Sen DK. Aetiological pattern of orbital tumors in India and their clinical presentations. A 20-year retrospective study. Orbit 1990;9:299–302.

6.Finger P, Harbour JW, Karcioglu ZA. Risk factors for metastasis in retinoblastoma [major review]. Surv Ophthalmol 2002; 47:1–16.

7.Shields CL, Shields JA. Recent developments in the management of retinoblastoma. J Pediatr Ophthalmol Strabismus

1999;36:8–18.

8.Finger PT, Czechonska G, Demirci H, Rausen A. Chemotherapy for retinoblastoma. A current topic. Drugs 1999;58: 983–996.

9.De Potter P. Current treatment of retinoblastoma. Curr Opin Ophthalmol 2002;13:331–336.

10.Belmekki M, El Bakkali M, Abdellah H, et al. Epidemiologie

des processus orbitaires chez l’enfant. J Fr Ophtalmol; 1999; 22:394–398.

11.Castillo BV, Kaufman L. Pediatric tumors of the eye and orbit. Pediatr Clin N Am 2003;50:149–172.

12.Doz F, Khelfaoui F, Mosseri V, et al. The role of chemotherapy in orbital involvement of retinoblastoma. The experience of a single institution with 33 patients. Cancer 1994;74:722– 732.

13.Grabowski FF, Abramson DH. Intraocular and extraocular retinoblastoma. Hematol Oncol Clin North Am 1987;1:721– 735.

14.Karcioglu ZA, Al-Mesfer SA, Jabak MH, et al. Work-up for metastatic retinoblastoma: a review of 261 patients. Ophthalmology 1997;104:307–312.

15.Rootman J, Hofbauer J, Ellsworth RM, et al. Orbital extension of retinoblastoma: a clinicopathological study. Can J Ophthalmol 1978;13:72–80.

16.Shields JA, Shields CL, Ehya H, et al. Fine needle aspiration biopsy of suspected intraocular tumors. The 1992 Urwick Lecture. Ophthalmology 1993;100:1677–1684.

17.Karcioglu ZA, Gordon RA, Karcioglu GL. Tumor seeding in ocular fine needle aspiration biopsy. Ophthalmology 1985;92: 1763–1767.

18.Stevenson KE, Hungerford J, Garner A. Local extraocular extension of retinoblastoma following intraocular surgery. Br J Ophthalmol 1989;73:739–742.

19.Karcioglu ZA. Fine needle biopsy for diagnosis of retinoblastoma. Retina 2002;22:707–710.

20.Shields CL, Honavar S, Shields JA, et al. Vitrectomy in eyes with unsuspected retinoblastoma. Ophthalmology 2000;107: 2250–2255.

21.Karcioglu ZA, Mullaney PB, Millar LC. Extrusion of porous polyethylene orbital implant in recurrent retinoblastoma.

Ophthalmic Plast Reconstr Surg 1998;14:37–44.

22.Dutton JJ, Byrne SF, Proia AD. Retinoblastoma. In: Diagnostic Atlas of Orbital Diseases. Philadelphia: WB Saunders; 2000:136–137.

23.Reese AB. Tumours of the Eye. London: Cassell & Company; 1951:138.

24.Mackay CJ, Abramson DH, Ellsworth RM. Metastatic patterns of retinoblastoma. Arch Ophthalmol 1984;102:391–396.

25.Hungerford J, Kingston J, Plowman N. Orbital recurrence of retinoblastoma. Ophthalmic Pediatr Genet 1987;8:63–68.

26.Goble RR, McKenzie J, Kingston JE, et al. Orbital recurrence of retinoblastoma successfully treated by combined therapy. Br J Ophthalmol 1990;74:97–98.

27.Kiratli H, Bilgic S, Ozerdem U. Management of massive orbital involvement of intraocular retinoblastoma. Ophthalmology 1998;105:322–326.

28.Svedberg-Winholt H, Al-Mesfer SA, Riley FC. Survival trends of retinoblastoma patients with extraocular extension. Paper presented at: Congress of European Society of Ophthalmology; 1999. Abstr 502.

29.Chantada G, Fandino A, Casak S, et al. Treatment of overt extraocular retinoblastoma. Med Pediatr Oncol 2003;40:158– 161.

30.Campbell R, Sobin LH. Histologic typing of tumors of the eye and its adnexa. WHO International Histological Classification of Tumors. Berlin: Springer-Verlag; 1998.

31.Shields JA, Shields CL. Massive orbital extension of posterior uveal melanoma. Ophthalmic Plast Reconstr Surg 1991;7: 238–251.

32.Starr HJ, Zimmerman LE. Extrascleral extension and orbital recurrence of malignant melanomas of the choroid and ciliary body. Int Ophthalmol Clin 1962;2:369–385.

33.Shields JA, Shields CL, Donoso LA. Management of posterior uveal melanoma. Surv Ophthalmol 1991;36:161–195.

34.Liarikos S, Rapidis AD, Roumeliotis A, et al. Secondary orbital melanomas: analysis of 15 cases. J Craniomaxillofac Surg 2000;28:148–152.

35.Shammas HF, Blodi FC. Orbital extension of choroidal and ciliary body melanomas. Arch Ophthalmol 1977;95:2002– 2005.

36.Rini FJ, Jakobiec FA, Hornblass A, et al. The treatment of advanced choroidal melanoma with massive orbital extension. Am J Ophthalmol 1987;104:634–639.

37.Affeldt JC, Minckler DS, Azen SP, et al. Prognosis in uveal melanoma with extrascleral extension. Arch Ophthalmol 1980;98:1975–1979.

38.Shields JA, Shields CL. Orbital malignant melanoma: 2002 Sean B. Murphy Lecture. Opthalmic Plast Reconstr Surg

2003;19:262–269.

39.Shields CL, Shields JA, De Potter P, et al. Diffuse choroidal melanoma. Clinical features predictive of metastasis. Arch Ophthalmol 1996;114:956–963.

40.Collaborative Ocular Melanoma Study Group. Histopathologic characteristics of uveal melanomas in eyes enucleated from Collaborative Ocular Melanoma Study COMS Report No 6. Am J Ophthalmol 1998;125:745–766.

41.Shields JA. Orbital malignant melanomas. In: Hornblass A, ed.

Ophthalmic Plastic & Reconstructive Surgery. Baltimore: Williams & Wilkins; 1988.

42.Henderson JW, Farrow GM. Orbital Tumors. 2nd ed, New York: BC Decker; 1980:425–450.

43.Gündüz K, Shields CL, Shields JA. Plaque radiotherapy for management of ciliary body and choroidal melanoma with extraocular extension. Am J Ophthalmol 2000;130:97–102.

44.Shields CL, Shields JA, Yarian DL, et al. Intracranial extension of choroidal melanoma near the optic nerve. Br J Ophthalmol 1987;71:172–176.

45.Shields JA, Augsburger JJ, Dougherty MJ. Orbital recurrence of choroidal melanoma 20 years after enucleation. Am J Ophthalmol 1984;97:767–770.

46.Shields JA, Augsburger JJ, Donoso LA, et al. Hepatic metastasis and orbital recurrence of uveal melanoma after 42 years. Am J Ophthalmol 1985;100:666–668.

47.Martin JA, Robertson DM. Extrascleral extension of choroidal melanoma diagnosed by ultrasound. Ophthalmology 1983;90: 1554.

48.Farah ME, Byrne SF, Hughes JR. Standardized echography in uveal melanoma with scleral or extraocular extension. Arch Ophthalmol 1984;102:1482.

49.Enochs SW, Petherick P, Bogdanova A, et al. Paramagnetic metal scavenging by melanin: MR imaging. Radiology 1997; 204:417–423.

50.Haik BG, Saint Louis L, Smith ME, et al. Magnetic resonance imaging in choroidal tumors. Ann Ophthalmol 1987;19:218– 238.

51.Gormori JM, Grossman RI, Shields JA, et al. Choroidal melanomas. Correlation of NMR spectroscopy and MR imaging. Radiology 1986;158:443–445.

52.Shields CL, Shields JA, Karlsson U, et al. Enucleation after plaque radiotherapy for posterior uveal melanoma. Ophthalmology 1990;97:1665–1670.

53.Pach JM, Robertson DM, Taney BS, et al. Prognostic factors in choroidal and ciliary body melanomas with extrascleral extension. Am J Ophthalmol 1986;101:325–331.

54.De Potter P, Shields JA, Shields CL, Santos R. Modified enucleation via lateral orbitotomy for choroidal melanoma with orbital extension: a report of two cases. Ophthalmic Plast Reconstr Surg 1992;8:109–113.

55.Shields JA, Shields CL, Suvarnamani C, et al. Orbital exenteration with eyelid sparing: indications, technique, and results. Ophthalmic Surg 1991;22:292–297.

56.Shields JA, Shields CL, Demirci H, et al. Experience with eyelid sparing orbital exenteration: the 2000 Tullos O. Coston Lecture. Ophthalmic Plast Reconstr Surg 2001:17:355–361.

57.Goldberg RA, Kim JW, Shorr N. Orbital exenteration: results of an individualized approach. Ophthalmic Plast Reconstr Surg 2003;19:299–336.

SECONDARY ORBITAL TUMORS ORIGINATING FROM THE SINONASAL TRACT

piratory tract neoplasms, more often in benign than in malignant lesions.13–15

SQUAMOUS CELL CARCINOMA

Nasal and paranasal sinus neoplasms account for approximately 5% of tumors originating in the upper respiratory tract. Approximately half of these tumors are benign, mainly squamous papillomas, and the remainder are malignancies, of which squamous cell carcinoma (SCC) comprises approximately 75% (Table 23.1).1,2

Epithelial Tumors

Benign epithelial tumors of the nose and paranasal sinuses include squamous and inverted papilloma and pleomorphic adenoma originating from minor salivary glands.2,3 Papillomas of the sinonasal tract originate from squamous or Schneiderian epithelium. Although they are benign, these tumors, which most commonly occur in white males after 50 years of age, may expand beyond their site of origin and invade the adjacent structures, including the orbit. Furthermore, these lesions recur when they are not excised completely and may show transition into squamous cell carcinoma.3–5 An associated malignancy, usually SCC, has been reported in approximately 10 to 15% of patients with inverted papilloma.6,7 Inverted papillomas may also develop in the lacrimal drainage system (LDS).5 Some of the benign lesions, including the inverted papillomas of the sinonasal tract and the LDS, are known to invade the orbit secondarily (Figure 23.1).6,8

Although malignant tumors of the nose and paranasal sinuses constitute only about 1% of all malignancies in the body, their influence on the neighboring orbit and ocular tissues is significant. Approximately 10% of all orbital mass lesions consist of secondary tumors originating from the nose and paranasal sinuses.9–11 Sinonasal malignancies occur more often in white males.12

Epidemiologic studies emphasize the influence of inhaled carcinogens, and there is also evidence that human papillomavirus (HPV) infection is an oncogenic factor in the development of paranasal upper res-

SCC is the most common malignant tumor of the sinonasal tract.2,16 Maxillary and ethmoid sinuses give origin to approximately 85% of SCC; the frontal and sphenoid sinuses are rarely involved with this tumor. In many instances, SCC has been associated with preexisting chronic sinusitis or may create secondary sinusitis owing to the obstruction of the sinusoidal ostium. Therefore, it is important to differentiate a malignancy from a coexistent inflammation.

Other malignant epithelial sinonasal tumors include adenocarcinoma and adenoid cystic carcinoma of minor salivary glands.7

CLINICAL FEATURES

The most common clinical manifestations of the sinonasal tumors are similar if not identical to the symptoms caused by inflammatory sinus disease, including fullness, pain, nasal airway obstruction, and nasal discharge. The physical examination of the sinonasal region and orbit should include a direct fiberoptic endoscopy, which also offers an opportunity to obtain tissue for diagnosis. Tissue material from these tumors can be collected with sinus lavage/ cytology, fine-needle aspiration biopsy (FNAB) and transnasal biopsy with direct or endoscopic approaches.

Once a tumor has extended into the orbit, however, the symptoms change somewhat and become more related to the eye and adnexal structures (Figures 23.2 and 23.3). Extension of the tumor usually takes place as an infiltrating fashion to create a spaceoccupying mass in the orbit with surrounding inflammatory reaction leading to proptosis, extraocular muscle motility disturbance, visual acuity and field loss, and edema of the eyelids and conjunctiva; epiphora may develop as a late symptom. The proptosis of the eye secondary to the infiltration of sinus tumors into the orbit is usually nonaxial and associated with a great deal of pain and paresthesia in about

75% of the cases. Metastatic disease to the orbit from distant organs, on the other hand, is painful in fewer cases and the proptosis is usually axial.17

An unusual inflammatory condition, which may mimic secondary orbital neoplasm, is allergic fungal disease of the nose and paransasal sinuses.18,19 This bizarre inflammatory process of the sinonasal tract may extend into the orbit (Figure 23.4). Frequently, an aspergillus species is the causative organism, but other

fungal species, including Fusarium and Rhizomucor, have also been incriminated.20

Although this allergic entity is considered to be confined to the lumen, without mucosal involvement, it nevertheless is known to spread from one paranasal cavity to the other and to the orbit.21 Computed tomography (CT) and magnetic resonance imaging (MRI) show bony expansion and remodeling of the involved cavity and focal bony erosion. The mucoid content of

FIGURE 23.2. A 40-year-old woman with squamous cell carcinoma of the orbit originating from the maxillary sinus. Although the tumor could be palpated in the inferior orbit, proptosis and motility disorders of the right eye were minimal.

the paranasal sinuses mixed with fungus balls produces low signal intensity in the MRI. The extensive bony expansion and irregular remodeling, coupled with bony erosion, may simulate an invasive tumor of the nose or the sinus, with secondary orbital invasion, such as esthesioneuroblastoma, leukemia/ lymphoma, or Burkitt’s lymphoma. The histopathology shows mucoid debris intermixed with numerous eosinophils and hyphae of the causative fungus, most of the time Aspergillus species.20,21

RADIOLOGIC FEATURES

Radiologic imaging is essential for the evaluation of the patient with plain films of the orbit and surrounding structures, as well as CT and MRI.12,22,23 In a great majority of the cases of SCC with orbit involvement, the bony wall of the orbit demonstrates erosion. CT provides better images of bone destruction, however, it does not reliably reveal the details of soft tissue invasion (Figure 23.3). In contrast, MRI provides a more accurate evaluation of the soft tissues, although it may be difficult to distinguish a tumor limited to the periorbita from early invasion. The involvement of the periorbita, however, cannot be assessed preoperatively even with the most sensitive imaging techniques and endoscopy.

Although bone destruction is considered to be pathognomonic of malignancy, not all malignant tumors destroy the adjacent bone. Some sinonasal sarcomas, lymphomas, and plasmacytomas remodel the adjacent bone by chronic compression. Therefore, if soft tissue detail is not available, one should remem-

FIGURE 23.3. (A–C) coronal and axial CT images reveal a large, partially necrotic maxillary sinus tumor extending into the adjacent paranasal sinuses and the orbit. Coronal, noncontrast CT scan depicts soft tissue mass in the right maxillary sinus extending into the nasal cavity, ethmoidal sinus, and orbit. The destruction of the orbital floor is clearly seen in the regular CT (A) and bone windows (C). Axial, noncontrast CT scan (B) also shows the extensive infiltration of the maxillary sinus tumor; nonhomogeneous soft tissue density fills the maxillary sinus and extends into the orbit and nasal cavity. The tumor’s mottled appearance is mostly likely due to necrosis because of presurgery radiation treatment. An exenteration specimen (D) from the same patient shows the extension of the squamous cell carcinoma from maxillary sinus into the orbital floor.

ber that tumors with benign-appearing bone changes may be aggressive, yet some other lesions that cause bone destruction, such as pyogenic or allergic fungal sinusitis, inflammatory pseudotumor, and mucocele, may be benign (Figure 23.4).23 Inflammatory pseudotumor of the maxillary sinus, unlike its orbital counterpart, may present with aggressive bone erosion into the orbit and mimic a secondary SCC.24

MRI, particularly with T2-weighted images, can be extremely useful in mapping the sinonasal tumors because of the inherent differences of signal intensity between SCC and inflammatory sinus disease. The sinonasal carcinomas usually present with homogeneous intermediate signal intensity on both T1and T2-weighted images because of their uniform cellular pattern.25 MRI may not help to differentiate a tumor as benign or malignant; however, it provides excellent delineation of the tumor from its surrounding inflammatory tissue.26 Sinonasal tumors obstruct the flow of mucosal secretions usually present with clinical symp-

FIGURE 23.4. (A) Axial CT image showing allergic sinonasal aspergillosis with expansion and remodeling of ethmoidal bones and the medial wall of orbit. (B) Histopathologic appearance shows acute inflammatory reaction with numerous eosinophils. Inset: Gomori silver methanamine stain showing many Aspergillus hyphae (arrows).

toms before the secretion becomes desiccated and therefore, offer a high signal intensity on T2-weighted images. In contrast, a great majority of sinonasal tumors are hypercellular and contain less water than the inflamed mucosa and noninspissated secretions; therefore, such tumors manifest with intermediate to low signal intensity on T2-weighted images. To confuse the issue, about 5% of sinonasal tumors such as neural and vascular tumors may have high signal intensity with T2 weighting. Enhancement of SCC with gadolinium chelate is particularly helpful on T1-weighted images in most sinonasal tumors.

The incidence and the presentation of orbital involvement by malignancies of the sinonasal tract vary with the site of origin and the type and aggressiveness of the tumor. SCC of the maxillary sinus involves the orbit in most cases through anatomic pathways such as the nasolacrimal duct or infraorbital fissure or by following neurovascular structures such as ethmoidal or infraorbital nerves.27 Direct invasion of the orbit by the destruction of the bone and periorbita is also commonly seen. Over the decades, surgeons have observed that the periorbita provides a resistant barrier against the infiltration of SCC, which becomes a very significant issue in the formation of the management plan. If the periorbita is not involved, the globe and the vital orbital tissues may be preserved. The invasion of the orbital periostium can best be documented during surgery by the use of frozen section.

The majority of the cases with orbital invasion attest to a relatively slow-growing tumor that went undetected until it became obvious with orbital symptoms. Orbital involvement, particularly with soft tissue invasion, represents the late presentation of the disease, with very poor prognosis.28

MANAGEMENT AND PROGNOSIS

The conventional treatment of the nasosinal SCC with extension into orbital soft tissues has been maxillectomy with orbital exenteration followed with or without radiation therapy. Even with extensive surgery and radiation, only 10 to 50% of these patients have dis- ease-free survival periods. Some have indicated that the preservation of the orbit through “planned exenteration” when there is localized invasion would not compromise the cure rate of these patients.29–32 Currently it is believed that localized invasion does not downgrade the outcome as long as the full thickness of the periorbita is not involved with tumor. It is also believed that preoperative or postoperative radiation therapy does not improve the survival rate in patients with total or partial exenterations.

ADENOCARCINOMA

Adenocarcinomas and adenoid cystic carcinomas of the sinonasal tract make up approximately 5% of all

its tumors.33 Although these carcinomas are rare, once they occur, they almost always invade neighboring structures, including the orbit.2

ESTHESIONEUROBLASTOMA

Esthesioneuroblastoma is a rare neoplasm that originates from the progenitor cells of the olfactory epithelium. Histopathologic diagnosis is difficult; antigen expression detected through a panel of antibodies by immunohistochemistry may be helpful. Expression of HASH as revealed by reverse transcriptase polymerase chain reaction (RT PCR) studies could be a specific marker of esthesioneuroblastoma.34 It occurs during the first and second, fifth, and sixth decades in a bimodal fashion, and its prognosis depends on the extent of the lesion. Tumor extending into the orbit and into the anterior cranial fossa is staged as T3 according to the UCLA classification (Figure 23.5).35,36 A combination of surgery and radiotherapy seems to be the optimum approach to treatment.37 The exact role of chemotherapy is unclear. Disease-free survival at 5 years averages 45% for stage 3 disease.38

Mesenchymal Tumors

Fibrous, fibromyxomatous, and fibro-osseous lesions are common benign tumors of the sinonasal tract. Although their growth is usually slow, they are known to extend into the orbit if they are located in an adjacent site (Figure 23.6).7,39

Malignant mesenchymal tumors including rhabdomyosarcoma, smooth muscle and neurogenic sarcomas, fibrosarcomas, alveolar soft part sarcoma, osteogenic sarcoma, malignant hemangiopericytoma, and, rarely, angiosarcoma are known to occur in the sinonasal tract and may invade the orbit secondarily.2

Lymphoproliferative Tumors

Lymphomas of the sinonasal tract are usually of the non-Hodgkin’s type that usually present in the very young and the very old.40 In adults, in whom the lymphoma rarely affects the orbit, the 5-year survival is approximately 45%. In children, the 5-year survival rate reaches to 70 to 80% if Burkitt’s lymphoma is excluded.

Burkitt’s lymphoma, which represents one of the most common types of pediatric non-Hodgkin’s lymphomas, is a highly aggressive, extranodal B-cell tumor (Figure 23.7). It is characterized by translocation and deregulation of the c-myc gene on chromosome 8. Endemic cases, which are usually seen in Africa, involve the cranial skeleton and mostly bear Epstein– Barr virus genomes. These are the tumors that usually present with orbital involvement (Figure 23.8). Sporadic cases, which are more often seen in the United States, usually involve the gastrointestinal and genitourinary systems. Non-Hodgkin’s lymphomas, including Burkitt’s lymphoma, develop in immunosuppressed individuals at a greater risk.41 Plasmacytoma as a part of systemic disease or a solitary lesion is also known to involve the bones of the nasal cav-

ity, paranasal sinuses, and the orbit. The bones of the head and neck region have an affinity to be the site of extramedullary plasmacytoma; 80 to 90% of the cases are found in the head and neck region, 40% of which originates in the sinonasal tract.

Other Tumors and Tumorlike Conditions

Inflammatory pseudotumor (myofibroblastic inflammation) is a space-occupying lesion that occurs in the paranasal sinuses. The pathogenesis of the lesion is not known.42 Histopathologically, it consists of fascicles of myofibroblastic cells mixed with nonspecific chronic inflammatory infiltrates consisting of lym-

phocytes and plasmacytes. Inflammatory pseudotumor is primarily seen in the lungs, but extrapulmonic forms may be encountered in the nose and paranasal sinuses. Although their histopathologic appearance is benign, these lesions may present a malignant biologic behavior with local aggression and even metastasis. Maxillary and ethmoidal pseudotumors may extend into the orbit through bony infiltration and thereby simulate squamous cell carcinoma. Biopsy is the only way to confirm the diagnosis.43

Langerhans cell and non–Langerhans cell histiocytoses commonly affect the nose, paranasal sinuses, and the orbit. Detailed discussion of this subject is given in Chapter 21.

SECONDARY ORBITAL TUMORS ORIGINATING FROM THE CRANIUM

Intracranial neoplasms, including sphenoid ridge meningioma and other cranial bone tumors, pituitary gland adenoma, craniopharyngioma, chiasmal tumors, and cysts, rarely extend into the orbit.43–46

Sphenoid Ridge Meningioma

Meningiomas of the sphenoid bone often lead to secondary invasion of the orbit.47 These tumors usually

FIGURE 23.7. Burkitt’s lymphoma is composed of a proliferation of mediumsized, noncleaved lymphocytes with scattered “tingible” macrophages presenting the classical “starry-sky” appearance (A,B).

(C) An immunohistochemical specimen revealing light chain positivity of tumor cells. (D) Transmission electronmicroscopy shows detail of noncleaved neoplastic lympocytes.

invade the superior orbital fissure and the optic canal and may compress the optic nerve and vascular structures, leading to venous congestion and orbital edema disproportional to the size of the space-occupying lesion in the orbit. Patients with optic canal and sphenoid bone meningiomas usually develop minimal and late proptosis that often becomes noticeable after severe visual loss. Proptosis occurs only when the tumor ruptures the dura and forms a space-occupying lesion within the orbit (Figure 23.9).

Meningioma of the sphenoid ridge most often presents as an “en plaque” neoplasm that slowly grows

FIGURE 23.9. Sphenoid ridge meningioma. (A) Intraoperative stereotactic views of the CT scan showing the extension of a left frontal lobe meningioma into the superior and lateral orbit. (B) T1weighted, contrast-enhanced axial MR image shows irregular ho-

mogeneous enhancement within the brain; the extension of the meningioma into the lateral orbit caused marked proptosis. (C) Gaze photographs, obtained 6 months postoperatively, show residual proptosis and extraocular motility deficit of the left eye.

as a flat lesion along the dural surface, extending into the foramina of the orbit (Figure 23.10). Depending on the location of the growth, it may extend into the optic canal and the superior and/or inferior orbital fissures, causing blindness, extraocular motility disturbance, and venous congestion in the orbit. Meningiomas of the ridge and the suprasellar area may present with bilateral papilledema, as opposed to the more commonly encountered unilateral disk edema of

the optic nerve meningioma. Intracanalicular meningioma produces early unilateral blindness. Olfactory groove meningioma, on the other hand, rarely produces early blindness because these lesions must become very large before they compress the visual system. Another presentation often associated with the meningioma of the olfactory groove is Foster–Kennedy syndrome, in which the tumor causes atrophy of one optic nerve early in its growth; later, the increased in-