Ординатура / Офтальмология / Английские материалы / Surgical Atlas of Orbital Diseases_Mallajosyula_2009

It is important to distinguish ossifying fibroma from fibrous dysplasia as the former lesion is more aggressive, and left alone, inexorably enlarges and may enter into the cranium. As incomplete excision frequently leads to recurrence6, complete surgical excision is the treatment of choice.

Osteoblastoma

This is a benign tumor composed of osteoblasts and is extremely rare in the orbit.11 It affects patients in the second to third decades and presents with a slowly progressive proptosis and globe displacement. The reported cases have arisen from the roof and

ethmoid sinuses and imaging shows an osteolytic lesion larger than 1 cm with a sclerotic margin. Histologically, trabeculae of lamellar bone with osteoblastic rimming are seen. The histological appearance is indistinguishable from that of osteoid osteoma (a lesion seen in long bones and measuring less than 1 cm in diameter).6 Surgical excision is the treatment of choice.

Chondroma

Chondromas are benign cartilaginous tumors that may rarely be encountered in the orbit, usually near the orbital rim or trochlea.12 Radiologically, they are

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seen as dense, well circumscribed masses. On histology, they are composed of lobules of mature cartilage.13 Excision is curative.

Cholesterol Granuloma

Cholesterol granuloma is a foreign body response to the presence of crystallized cholesterol. It commonly involves the middle ear and temporal bone, but the orbit may rarely be affected. In the orbit, it occurs almost exclusively in the superolateral frontal bone.14, 15

Males in the fourth to fifth decades of life are predominantly affected. The usual presentation is that of a slowly progressive superolateral mass resulting in inferior globe displacement, proptosis and diplopia in upgaze. There may be associated headache or pain and a history of trauma may be elicited in some patients.

CT imaging demonstrates an osteolytic lesion expanding and eroding the frontal bone and extending into the orbit and intracranially.14, 15 With MRI, high signal intensities are seen on both T1 and T2 weighted images (similar to dermoid cysts).

Histology is characterised by the presence of numerous cholesterol clefts and an associated foreign body giant cell reaction.

Curettage of the lesion via a percutaneous approach is curative. An endoscope may be helpful in visualizing areas behind the superior orbital rim.16

CASE ILLUSTRATION (Figures 13.3A to F)

Aneurysmal Bone Cyst

This cystic lesion of the bone is rare in the orbit and usually presents with a painless proptosis in the second decade of life.17 Sudden progression may occur following an intralesional hemorrhage. Imaging shows a destructive, expansile bony lesion usually involving the roof of the orbit. Curettage of the lesion is curative and histological examination shows blood filled fibrous spaces that lack an endothelial lining. Hemosiderin laden macrophages and bony trabeculae are seen in the fibrous stroma surrounding the spaces.3

Giant Cell Lesions

A histological picture dominated by giant cells is seen in three different lesions: giant cell tumor, giant cell granuloma and ‘brown tumor’ of hyperparathyroidism. Giant cell tumor or osteoclastoma is usually seen in epiphyses of long bones and affects patients between the ages of 25-40 years.6 It uncommonly involves the paranasal sinuses and can secondarily impinge upon the orbit.6 Histology shows evenly scattered multinucleated giant cells containing between 10-100 nuclei. The stromal cells contain nuclei resembling those of the giant cells.6 En bloc excision is usually curative.

Giant cell granuloma, also known as giant cell reparative granuloma, is a rare destructive lesion of bone that presents with proptosis and globe displacement.18 Headache and pain may also be present. In contrast to giant cell tumor, giant cell granuloma is seen in younger patients (average age 18.6 years) and on histology, the giant cells are sparse and unevenly distributed and reactive new bone formation may be seen.6 This lesion responds well to curettage.

‘Brown tumor’ is histologically almost indistinguishable from giant cell granuloma. Clinically, however, it is associated with primary or secondary hyperparathyroidism. The increased osteoclastic activity leads to focal areas of bone resorption and hemorrhage. As treatment of hyperparathyroidism usually results in spontaneous healing of the bony lesion, it is important that a careful clinical evaluation is performed in patients with histology suspicious for ‘brown tumor’.19

Osteogenic Sarcoma

Osteogenic sarcoma of the orbit is rare and is seen in the 4th and 5th decades of life in patients who have usually undergone previous radiotherapy for retinoblastoma or fibrous dyplasia.6 Primary orbital involvement is exceedingly rare.20 It develops rapidly over a period of weeks to months and can present with proptosis, pain, diplopia and visual impairment. Imaging shows a mixed lytic and sclerotic mass with indistinct margins. Histology shows sarcomatous

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Chondrosarcoma

These are slow-growing, non-metastasizing locally aggressive tumors commonly arising in the paranasal sinuses and invading the orbit.13 Imaging reveals a well-defined osteolytic lesion with internal stippling. Multiple lobules of hypercellular cartilage with binucleate cells in lacunae and mitotic figures are seen on microscopy. Treatment is by radical resection but complete removal may not be possible in the craniofacial region and multiple recurrences may be seen.13

Mesenchymal Chondrosarcoma

This variant of chondrosarcoma has a predilection for the head and neck region. It may occur in the soft tissues of the orbit, almost exclusively in females in the second and third decades of life.21 The clinical course is rapid and patients present with proptosis and infiltrative effects of less than a year’s duration. Imaging shows a non-specific, irregular, mottled soft tissue mass. On histology areas of poorly differentiated mesenchymal cells intermixed with lobules of mature cartilage are seen. As metastasis, especially to the lungs, can occur, exenteration is the treatment of choice.21

Ewing’s Sarcoma

This is a small round cell tumor of bone mainly affecting patients in the first two decades. Orbital involvement is usually by metastases or spread from adjacent areas (Ewing’s sarcoma is responsible for 10% of pediatric orbital metastasis). Primary Ewing’s sarcoma of the orbit is exceedingly rare.22 Clinically, a rapidly developing non-axial proptosis is noted and imaging reveals expansile mass with bone destruction. Microscopy shows a featureless small round cell proliferation. PAS positive glycogen granules may be seen in the cytoplasm. Immunohistiochemistry (for CD99) is helpful in making the diagnosis. Treatment is by chemotherapy followed by resection or radiotherapy.

Myeloma

Multiple myeloma or solitary plasmacytoma may involve the orbit, usually in patients older than 50 years of age.23 Presentation is with subacute onset of pain and proptosis. An osteolytic area with a contiguous soft tissue mass is seen on imaging. Histology shows sheets of malignant plasma cells. The orbital lesions are treated with radiotherapy and chemotherapy is used for systemic disease.

Langerhans’ Cell Histiocytosis (LCH)

LCH results from an abnormal proliferation of Langerhans’ cellsspecialized histiocytic cells normally seen in the epidermis and characterised by ‘racquet-shaped’ cytoplasmic granules (Birbeck granules) on electron microscopy. One form of LCH, previously known as eosinophilic granuloma, preferentially affects the skull and presents as a localized lytic lesion of bone. The disease is usually seen in young males and the children classically present with proptosis secondary to a superolateral orbital lesion.24 On CT, a central radiolucent area with an enhancing rim is seen. Histologically, a granulomatous infiltrate with Langerhans’ cells and prominent eosinophils is observed. The treatment of choice is curettage, though intralesional steroid injections and low-dose radiotherapy have also been used. An endoscopic aided curettage may achieve complete removal of the lesion.

CASE ILLUSTRATION (Figures 13.4A to D)

Intraosseous Hemangioma

This is a rare vascular tumor which presents as a slowly developing orbital mass, often associated with pain or tenderness.25 The frontal bone is usually affected and on CT, a well-defined, radiolucent mass that expands the inner and outer tables of the bone is seen. Histologically, the lesions are hemangiomas composed of thin-walled vascular spaces lined by endothelium. Treatment is by surgical excision of the lesion with a rim of normal bone. Preoperative angiography should be performed.

REFERENCES

1.Rootman J, Chang W, Jones D. Distribution and differential diagnosis of orbital disease. In: Rootman J, ed. Diseases of the orbit, 2nd ed. Philadelphia: Lippincott Williams and Wilkins, 2003;53-84.

2.Shields JA, Bakewell B, Augsburger JJ, Flanagan JC. Classification and incidence of space-occupying lesions of the orbit: a survey of 645 biopsies. Arch Ophthalmol 1984;102:1606-11.

3.Selva D, White VA, O’Connell JX. Primary bone tumors of the orbit. Surv Ophthalmol 2004;49:328-42.

4.Henderson JW. Fibro-osseus, osseus, and cartilaginous tumors of orbital bone. In: Henderson JW, ed. Orbital tumors, 3rd ed. Philadelphia: Raven Press, 1994.

5.McNab AA,. Orbital osteoma in Gardner’s syndrome. Aust NZ J Ophthalmol 1998;26:169-70.

6.Fu YS, Perzin KH. Nonepithelial tumors of the nasal cavity, paranasal sinuses and nasopharynx: a clinicopathologic study. II. Osseus and fibro-osseus lesions, including osteoma, fibrous dysplasia, ossifying fibroma, osteoblastoma, giant cell tumor, and osteosarcoma. Cancer 1974;33:1289-305.

7.Chen C, Selva D, Wormald PJ. Endoscopic modified lothrop procedure: an alternative for frontal osteoma excision. Rhinology 2004;42:239-43.

8.Katz BJ, Nerad JA. Ophthalmic manifestations of fibrous dysplasia. Ophthalmology 1998;105:2207-15.

9.Jackson IT, Hide TA, Gomuwka PK, et al. Treatment of cranio-orbital fibrous dysplasia. J Maxillofac Surg 1982;10:138-41.

10.Margo CE, Weiss A, Habal MB. Psammomatoid ossifying fibroma. Arch Ophthalmol 1986;104:1347-51.

11.Leone CR, Lawton AW, Leone RT. Benign osteoblastoma of the orbit. Ophthalmology 1988;95:1554-8.

12.Jepson CM, Wetzig PC. Pure chondroma of the trochlea. Surv Ophthalmol 1966;11:656-9.

13.Fu YS, Perzin KH. Non-epithelial tumors of the nasal cavity, paranasal sinuses and nasopharynx: a clinicopathologic study. III. Cartilaginous tumors (chondroma, chondrosarcoma). Cancer 1974;34:453-63.

14.Arat YO, Chaudhry IA, Boniuk M. Orbitofrontal cholesterol granuloma: distinct diagnostic features and management. Ophthal Plast Reconstr Surg 2003;19:382-7.

15.McNab AA, Wright JE. Orbitofrontal cholesterol granuloma. Ophthalmology 1990;97:28-32.

16.Selva D, Chen C. Endoscopic approach to orbitofrontal cholesterol granuloma. Orbit 2004;22:49-52.

17.Ronner HJ, Jones IS. Aneurysmal bone cyst of the orbit: a review. Ann Ophthalmol 1983;15:626-9.

18.Spraul CW, Wojno TH, Grossniklaus HE, Lang GK. Reparative giant cell granuloma with orbital involvement. Klin MonatsblAugenheilkd 1997;211:133-4.

19.Parrish CM, O’Day DM. Brown tumor of the orbit. Arch Ophthalmol 1986;104:1199-202.

20.Parmar DN, Luthert PJ, Cree IA, et al. Two unusual osteogenic orbital tumors: presumed parosteal osteosarcomas of the orbit. Ophthalmology 2001;108:1452-6.

21.Guccion R, Font R, Enzinger F, Zimmerman L. Extraskeletal mesenchymal chondrosarcoma. Arch Pathol 1973;95:336.

22.Guzowski M, Tumuluri K, Walker DM, Maloof A. Primary orbital Ewing sarcoma in a middle-aged man. Ophthal Plast Reconstr Surg 2005;21:449-51.

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23.Rodman HI, Font RL. Orbital involvement in multiple myeloma: review of the literature and report of three cases. Arch Ophthalmol 1972;87:30-5.

24.Jordan DR, McDonald H, Noel L, Nizalik E. Eosinophilic granuloma. Arch Ophthalmol 1994;111:134-5.

25.Relf S`J, Bartley GB, Unni KK. Primary orbital intraosseus hemangioma. Ophthalmology 1991;98:541-7.

Mass lesions of the lacrimal gland fossa account for a substantial proportion of orbital space-occupying lesions. These are mainly inflammatory, structural and neoplastic lesions.

These lesions can be broadly classified as:1

Inflammatory Lesions

1.Infective

i.Bacterial

ii.Viral

2.Non-infective

a.Idiopathic

b.Specific

i.Sjogren's syndrome

ii.Sarcoidosis

iii.Wegener's granulomatosis

Structural Lesions

1.Epithelial Cyst (Dacryops)

2.Dermoid

3.Mucocele

4.Implantation cyst

Neoplastic Lesions

1.Epithelial neoplasms

a. Benign Epithelial neoplasms

i.Pleomorphic adenoma

ii.Oncocytoma

iii.Warthin's tumor

iv.Myoepithelioma

b.Malignant Epithelial neoplasms

i.Adenoid cystic carcinoma

ii.Carcinoma in pleomorphic adenoma

iii.Mucoepidermoid carcinoma

iv.Adenocarcinoma and ductal carcinoma

v.Low grade carcinoma

vi.Other rare neoplasms

—Acinic cell

—Epithelial myoepithelial carcinoma

—Sebaceous adenocarcinoma

The main focus of this section will be a discussion of common lesions.

Epithelial Cyst (Dacryops)

The term Dacryops may be used to mean any simple cyst of the lacrimal gland, whether it is in the palpebral or orbital lobe.2

Clinical Features

Dacryops characteristically occurs in young adults or middle aged patients, as a unilateral or bilateral, painless, non-tender, fluctuant mass in the forniceal conjunctiva supero-temporally. Most cysts either remain relatively stable or demonstrate slow progression.

The diagnosis can usually be made clinically. It may be difficult to differentiate a dacryops clinically from a simple epithelial cyst of conjunctival origin, which are commoner in nasal portion. It can be differentiated from a dermoid cyst by the fact that the latter is usually attached to bone.

Pathology and Pathogenesis

Grossly, the classic dacryops is a round cyst that contains clear fluid (tears) and is lined by epithelium. The epithelium may consist of one or two layers of relatively flat cells similar to those found in a lacrimal gland duct, or it may be composed of nonkeratinizing stratified epithelium with goblet cells similar to those in the conjunctiva. Normal lacrimal gland tissue is usually identified in the histologic specimen adjacent to the cyst.

It is believed that a dacryops results from obstruction of one of the secretory ducts of the lacrimal gland.3 The obstruction results in progressive dilatation of the duct with formation of a thin walled cyst.

Management

When a dacryops is small and asymptomatic no treatment is necessary. If it is larger and symptomatic, it can be managed by simple aspiration. Aspiration can lead to recurrence, so it is advisable to remove the lesion surgically using either a conjunctival approach or a lateral orbitotomy.

Prognosis

The prognosis for vision and life is excellent. Complications associated with a dry eye may occur if an excessive amount of lacrimal gland tissue and duct is removed.

CASE ILLUSTRATIONS

Case 1

Mr V, 47 years male, presented with complaints of recurring redness and itching in both eyes. The patient had been diagnosed earlier as a case of allergic conjunctivitis and was treated accordingly. He also had small, round, non-tender, cystic lesions in the lacrimal gland area on both the sides. So the patient was diagnosed to be a case of dacryops in both eyes and was advised excision. (Figures 14.1A and B).

Pleomorphic Adenoma

Pleomorphic adenoma is the most common benign epithelial tumor of the lacrimal gland. Typically they occur at a younger age (2nd-5th decades) than malignant tumors.

Tumors of Lacrimal Gland 191

A

B

Figures 14.1A and B: Mr V, with clear, cystic lesions

(Dacryops) in both eyes

Clinical Features

The characteristic presentation is of a slowly progressive (more than a year), painless proptosis, downward globe displacement and swelling of the upper lid, unassociated with inflammatory signs or symptoms. Larger tumors may indent the globe and cause blurring of vision and may cause diplopia. The common signs consist of proptosis, usually non-tender, palpable mass in the superotemporal quadrant, downward and inward globe displacement and sometimes restricted upgaze. Fundus examination may show globe indentation in larger tumors and also choroidal folds sometimes.

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Imaging

Pleomorphic adenoma is best seen on CT scan. Usually a well circumscribed, homogenous or heterogenous, moderate to markedly enhancing soft tissue mass lesion is seen in the area of lacrimal gland. The scans may show pressure indentation over globe and expansion of the lacrimal fossa, suggesting chronicity of the lesion, in most cases. The mass may have few hyperdense areas suggestive of calcification. Ultrasound may reflect the histologic pattern with a highly reflective pseudocapsule, cystic spaces, and a well demarcated mass.

Pathology and Pathogenesis

The pleomorphic adenoma of the lacrimal gland is characteristically firm, grayish-white, encapsulated and bosselated mass on gross examination. Histologically, the tumor is composed of both epithelial and mesenchymal elements. The epithelial elements take the form of ducts, cords and squamous pearls. The mesenchymal elements usually include myxoid and chondroid tissue and sometimes osseous tissue. The diverse patterns of two components account for the name, pleomorphic adenoma. An important feature is the presence of microscopic nodular extensions into the pseudocapsule. This may account for the tendency of the tumor to recur when appropriate margins are not taken. The pathogenesis is not clear. It appears that both the cellular and stromal elements are derived from epithelial cells lining the acini and ducts.

Management

If there is a strong clinical suspicion of the lacrimal gland tumor being pleomorphic adenoma, on the basis of slow growing lesion, and absence of pain, motility disturbance and bony expansion, then it is best to excise the tumor completely without capsular rupture and without a prior incisional biopsy. Incomplete excision or capsular rupture may lead to a recurrence, sometimes with malignant transformation. Therefore, an incisional biopsy is probably contraindicated if the diagnosis is strongly suspected clinically.

The most appropriate approach is by a modified lateral orbitotomy. The important aspects are wide surgical exposure, excision of the periorbita, careful manipulation of the tumor to avoid rupture, removal

of a margin or adjacent tissue, and where possible, preservation of the uninvolved palpebral lobe (reducing the incidence of postoperative filamentary keratopathy).

Prognosis

The prognosis of the patient with pleomorphic adenoma of the lacrimal gland is generally very good. It is likely that greater attention to a complete en bloc excision will decrease the chance of recurrence and malignant transformation.

Case 2

Ms P, 20 years female, presented to me with protrusion of the right eyeball for 1 year, associated with reduced visual acuity. She had gradually increasing non-axial proptosis of the right eyeball. As you see in the figure (Figure 14.2A) the eyeball was displaced down and in. I could palpate a hard, non-reducible mass in the right supero-temporal orbit. There was neither tenderness nor any sign of inflammation. The mass was not pulsatile. The extraocular motility of right eye was restricted in upgaze, dextroelevation and dextroversion. Anterior segment of both the eyes were within normal limits, but the fundus of the right eye had folds of the internal limiting membrane, suggesting indentation of the globe by tumor.

Her CT scan (Figures 14.3A and B) showed a fairly well defined orbital mass in the area of lacrimal gland. The mass was indenting over the globe. No bony erosions could be seen. The moulding of the orbital wall contours suggested chronic and benign nature of the lesion.

My clinical diagnosis was right lacimal gland tumor, most probably a pleomorphic.

Adenoma: I did lateral orbitotomy to excise off the tumor completely. Cryoextraction of the tumor was done. It was a well encapsulated grayish white mass measuring 2.6 × 2 × 1.5 cm. (Figure 14.4A). Gross examination of the cut section showed grayish and chalky white areas and also cystic areas filled with mucin material.

Histopathologic examination (Figure 14.4B) showed a dimorphic picture with epithelial and stromal cells in close proximation. There were glandular and dilated cystic spaces lined by double