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

194 Surgical Atlas of Orbital Diseases

layered cuboidal cells with secretions in the lumen. Stroma consisted of basaloid cells with spindle appearance, indistinct cell borders with elongated vesicular nucleus with stellate pattern. There was abundant myxoid matrix in between the stromal cells.

These all histopathologic features confirmed the diagnosis of Pleomorphic Adenoma of Lacrimal Gland, right orbit. Postoperatively, proptosis resolved completely (Figure 14.2B).

Case 3

Mr K, 50 years old male presented to us with severe pain, swelling and redness of right periocular area for 15 days. He gave the history of gradually increasing painful protrusion of the right eyeball for about a month for which he underwent evisceration 2 weeks back. On examination, I could palpate a moderate to hard mass filling the supero-temporal and temporal part of right orbit. The lids and adnexa were inflamed with conjunctival chemosis (Figure 14.5A). CT scan orbit was done which showed a well circumscribed, soft tissue mass in the supero-lateral quadrant of right orbit (Figures 14.6A and B). The mass was mildly enhancing on contrast. There were no bony erosions. A disfigured globe (S/P evisceration) was seen. So, now clinically, the sequence of events that I thought was; the patient had gradually progressing lacrimal gland tumor (most probably pleomorphic adenoma) which lead to severe proptosis with exposure keratopathy and/

or perforated corneal ulcer. The previous surgeon had addressed the corneal complication by performing evisceration, without tackling the primary cause, i.e. lacrimal gland tumor.

I did lateral orbitotomy to excise off the tumor completely. Cryoextraction of the tumor was performed (Figure 14.7). Histopathologic examination of this well encapsulated tumor showed cells arranged in dimorphic pattern. The background showed myxoid stroma in between. These features were consistant with Pleomorphic Adenoma of Lacrimal Gland, right orbit. He was provided with a prosthesis after the postoperative edema subsided and the patient was comfortable (Figure 14.5B).

Adenoid Cystic Carcinoma

Adenoid Cystic Carcinoma (ACC) is the most common malignant epithelial tumor of the lacrimal gland. It has a tendency for bimodal occurrence i.e. more common in 2nd and 4th decades.

Clinical Features

The most important feature is a short duration of onset, i.e. usually few months. Generally patients also complain of having persisting pain, usually associated with paresthesia. Other clinical features include those which are seen in other lacrimal gland tumors as well. To enumerate, these are; a mass lesion in superotemporal quadrant, proptosis, downward and nasal displacement of the globe, ptosis and decreased visual acuity.

Figure 14.5A: Preoperative picture of Mr K. Note the superior sulcus fullness

Figure 14.5B: Postoperative appearance of patient with readymade ocular prosthesis

Figure 14.7: Gross appearance of the lacrimal gland tumor (Pleomorphic adenoma) along with a bone piece from lateral orbital wall

may show the tumor as isointense to brain and extraocular muscles.

Pathology and Pathogenesis

On gross examination, adenoid cystic carcinomas are usually grayish white, firm and may give a false impression of being circumscribed or pseudoencapsulated. Histopathologically, ACC has solid areas or cords of malignant epithelial cells. It can be divided into several histologic subtypes:

1.Cribriform (Glandular or Swiss cheese) pattern: Shows multiple lobules with many small clear spaces, giving it a cribriform appearance.

2.Sclerosing variant: Consists of hyalinized cylinders of connective tissue and elongated epithelial cords, surrounded by a dense hyalinized stroma.

Imaging

CT scan is the imaging modality of choice. An important feature (that differentiates many malignant lesion from a benign one) is bony erosions or osteolytic changes in the adjacent bone. Other features that help me to say that the lacrimal gland tumor is Adenoid Cystic Carcinoma are irregular margins of the lesion and its extension towards the orbital apex. But on CT scan, the lesion may actually appear to be a well defined, solid and fairly homogenous and hence can be easily confused with a benign lesion. Presence or absence of calcification doesn't help much. In MRI, the T2 weighted images

3.Basaloid variant: Shows solid epithelial lobules with large basophilic nuclei and scanty cytoplasm that resembles the lobules seen in basal cell carcinoma.

4.Comedocarcinoma variant: Shows epithelial lobules with large foci of central necrosis.

5.Tubular (Ductal) variant: Is composed of elongated and comma shaped epithelial tubules lined by two or three layers of cells.

In practical terms, cribriform is the most common pattern. Basaloid pattern is the least common but is most aggressive and therefore has the worst prognosis.

196 Surgical Atlas of Orbital Diseases

Management

The mainstay of managing ACC remains complete surgical excision with adjuvant radiotherapy and chemotherapy. For very well defined lesions, local excision with the adjacent bone removal should be done; for not so well defined lesions, orbital exenteration and for tumors that have extended into the bone or soft tissues of the orbit, radical en bloc orbitectomy by a multidisciplinary team should be done. As it is difficult to ensure complete tumor excision, surgery should be followed by adjuvant radical external beam radiotherapy. This EBRT may prevent or delay local recurrence.

The role of local, regional or systemic chemotherapy remains unclear in what is essentially an indolent tumor. We used a combination of carboplatin or cisplatin with 5-fluorouracil or doxorubicin in our patients as postoperative adjuvant therapy.4 Among all the treatment options, chemotherapy has the greatest potential to eradicate occult metastatic disease.

Prognosis

What so ever we may do, the prognosis of adenoid cystic carcinoma remains dismal. The usual clinical course of ACC is painful local and regional recurrence followed by distant metastasis, usually to the lungs. Tumor can recur even at a very late date (even 20 years later). Most patients die within 5 years of recurrence.

Case 4

This patient Mrs B, 18 years old female, presented to me with left blepharoptosis and mild enophthalmos. She gave the history of orbitotomy done elsewhere on left side for orbital tumor (as is evident from eyebrow scar in the picture) (Figure 14.8), about 5 years back. Old CT scan report (CT scan films were not available) suggested inhomogenous soft tissue mass in supero-lateral quadrant of left orbit. There was orbital fossa formation without bony erosions or intracranial extension. She was not aware of previous diagnosis nor was any histopathologic report available. I did Tarsofrontal Sling (Silicon rod sling) for her and advised her for CT scan orbits and regular follow up to rule out any tumor recurrence in future (Figure 14.9).

But the patient was lost to follow up for about 18 months, and therefter reported with massive proptosis and exposure keratopathy which had subacute onset (Figures 14.10A and B). CT scan done at this stage revealed a large heterogenous mass in the supero-lateral aspect of left orbit (Figures 14.11A and B). The mass was large enough to end just short of orbital apex. Roof of the left orbit appeared eroded at places but no obvious bony breach or intracranial extension was seen.

Clinical and radiological findings suggested that I was dealing with a recurrence of Lacrimal Gland Tumor, and that too a malignant one. I sent a

small tissue for cytology which strongly favored the diagnosis of Adenoid Cystic Carcinoma. Finally, I did lid sparing orbital exenteration (Figure 14.12A) and sent the specimen for histopathologic examination.

Histopathologic examination (Figure 14.12B) showed tumor cells arranged in cribriform pattern

with abundant mucoid matrix in extracellular spaces. The features were consistant with Adenoid Cystic Carcinoma of lacrimal gland. The patient was referred to an oncologist to rule out systemic metastasis and give adjuvant radiotherapy and chemotherapy.

REFERENCES

1.Diseases of Orbit, Textbook, 2nd Edition, Rootman J, Lippincott Williams and Wilkins, Chapter - Neoplasia, Page 344-45.

2.Bullock JD, Fleishman JA, Rosset JS: Lacrimal ductal cysts. Ophthalmol 1986;93:1355-60.

3.Smith S, Rootman J: Lacrimal ductal cysts. Presentation and management. Surv Ophthalmol 1986;30:245-50.

4.Muthy R, et al. Adenoid Cystic Carcinoma of the Lacrimal Gland: Management and Outcome. (Unpublished data).

Cystic lesions of the orbit are not uncommon. A true orbital cyst is any closed cavity or sac within the bony orbital confines that is lined with epithelium and contains a liquid or semisolid materials.1 The cysts may be developmental or acquired.

Developmental cysts

•Dermoid / Epidermoid

•Cytic teratomas

•Encephalocele

•Congenital cystic eye

•Perioptic hygromas.

Acquired cysts

•Dacryops

•Mucocele

•Dacryocele or amniontocele

•Hematic cyst

•Simple retention cysts

•Epithelial implantation cysts

•Chocolate cysts

•Parasitic cysts like cysticercosis and hydatid cyst

•Cystic degeneration of certain tumors like lymphangiomas, optic nerve gliomas and schwannomas.

Another classification proposed by Shields JA and Shields CL2 for pediatric cystic lesions of the orbit is as follows:

1.Cysts of surface epithelium: These are further divided into:

•Simple epithelial cyst (Epidermal, conjunctival and apocrine gland cysts)

•Dermoid cysts (Epidermal and conjunctival cysts).

2.Neural cysts: Further divided as:

•Those associated with ocular maldevelopment like congenital cystic eye and colobomatous cyst.

•Those associated with brain and meningeal tissues like cephalocele and optic nerve meningocele.

3.Secondary cysts: The most important secondary cyst is mucocele occurring in children secondary to cystic fibrosis.

4.Inflammatory cysts: These include parasitic cysts like cysticercosis and hydatid cyst.

5.Noncystic lesions with cystic component: These include certain tumors like adenoid cystic carcinoma, rhabdomyosarcomas and lymphangiomas.

Parasitic encystment is more often an inflammatory granuloma. Hematic cysts are not lined with epithelium but with a fibrous encapsulation of blood or blood products. Malignant epithelial neoplasm that secondarily invades the orbit may develop central necrosis.

Parasitic cysts is being dealt as a separate chapter in this book. Cystic degeneration of tumors is discussed in their respective chapters.

200 Surgical Atlas of Orbital Diseases

DERMOID AND EPIDERMOID CYSTS

Dermoid cysts are among the most common periorbital tumors presenting in childhood3,4 (Figure 15.1). Its, incidence is 33% of all orbital cysts. Dermoid and Epidermoid cysts are choriostomas that arise from subcutaneous epidermal rests or epidermal tissues trapped along bony suture lines during embryonic development.

These cysts are present congenitally and enlarge progressively. The superficial cysts are symptomatic in childhood but deeper dermoid may not be clinically symptomatic till in adulthood. The epidermoid enlarges and develops into a cyst lined with stratified squamous epithelium, which usually is attached to the fronto-zygomatic suture superotemporally or to the naso-frontal suture superonasally. If the cyst wall contains skin appendages such as hair follicles, sweat glands or sebaceous glands, the cysts are termed as dermoid cyst.5

If skin appendages are absent, the cysts are termed as epidermoid cyst.6 Preseptal orbital dermoid cyst occurs most commonly in the area of lateral brow adjacent to fronto-zygomatic suture. Duane's experience is that these cysts have occurred with equal frequency both nasally and temporally. Medial lesions in the infant should be distinguished from congenital encephaloceles or amniontoceles.

The mass is painless, smooth, ovoid to round in shape and firm to rubbery in consistency (Figure 15.4). It is immobile, being relatively attached to the periostium of the underlying suture. But it is not

attached to the overlying skin. In adulthood dermoid cysts may have a more posterior location.7 The posterior located cysts may be difficult to palpate. Proptosis and globe displacement are common. Long standing dermoid in the superior orbit may completely erode the roof and become adherent to duramater. Rarely an orbital cyst may pass through bony sutureline to extend intracranially or into the temporal fossa. Pressure placed on the extracranial portion of such a bilobed cyst may be transmitted through the bony dehiscence into the orbit and is a cause for the mastication proptosis reported by Bullock.8

Less commonly, orbital inflammation may be the presenting sign due to leakage of oil or keratin from the cysts.

Expansion of the dermoid cyst and inflammatory response to leakage may results in an orbital cutaneous fistula, usually following incomplete surgical removal.

Investigations

CT scan may show a heterogenous lesion with rim enhancement, calcification, fossa formation in the bone (Figure 15.2), bone erosion, bone sclerosis and intracranial extension.

MRI

Particularly important to see the cystic nature of the lesion when the cyst present as an inflammatory orbitopathy with surrounding tissue reaction.

Figure 15.1: A 9 months old female child with cystic swelling in lower part of orbit

Figure 15.2: CT scan of left orbit showing cystic space in lower part of orbit

Treatment

Surgical excision is the treatment of choice. Superficial cyst in childhood can be excised through an incision directly over the lesion or preferably through upper lid crease. A posteriorly located cyst may require more careful planning for an approach through an anterior or lateral orbital route9,10 (Figure 15.3).

Cysts located along the superior orbital roof with intracranial extension needs neurosurgical consultations and possible transcranial approach.11,12 It is important to keep the cyst wall intact during surgery. Intraoperative rupture with release of its contents may incite granulomatous inflammation. When an inadvertent rupture occurs operating area must be flooded with irrigating solution. Complete removal of the cyst wall is curative (Figures 15.4 and 15.5). Incomplete removal may lead to recurrence.9

TERATOMAS

Like dermoids teratomas are congenital tumor and choristomas.13,14 Dermoid and epidermiod cysts are developed from one germ layer but teratomas arise from two or more germ layers, including ectoderm and endoderm or mesoderm or both.15 Tumors may present at any age, many at or shortly after birth. Elsewhere teratomas are common in the gonads, mediastinum and pineal area. More than 50 cases have been reported in the orbit.16,17

Histologically, the tissues are usually matured and consist of ectoderm represented by keratinized

Figure 15.3: Inferior orbitotomy for complete removal of cyst

Cystic Lesions of Orbit 201

Figure 15.4: Dermoid cyst after removal

Figure 15.5: Case 5 days postoperatively

squamous epithelium and adnexal glandular structures; mesoderm by fibrous tissue, cartilage, fat, muscle and or bone; endoderm by gastrointestinal mucosa and glandular tissue and neuroectoderm by mature brain.16,17

Indication for surgery is unacceptable cosmetic appearance to the patient. One should preserve the globe whenever possible.18 Incomplete removal leads to recurrence. Exenteration is sometimes preferred because of fear of malignancy.15

CEPHALOCELE

A congenital dehiscence in the bony cranium may enable the meningeal tissue to herniate into the orbit forming cystic structure filled with CSF – an orbital meningocele. If brain protrudes inside the sac the

202 Surgical Atlas of Orbital Diseases

condition is termed as meningo-encephalocele. It may be fronto-ethmoidal or sphenoidal.19,20

Presentation is usually during infancy and childhood. It may present with pulsatile proptosis. Common site is superomedial aspect of the orbit. The mass is soft in consistency. The size of mass is increased by straining, bending forward or weight lifting. The direction of proptosis is inferotemporal. It may present with enophthalmos due to compression of orbital contents.21

Following conditions may be associated with encephalocele:22

1.Neurofibromatosis

2.Hypertelorism

3.Malar or orbital bone depression

4.Optic atrophy

5.Optic nerve coloboma

6.Optic nerve glioma

7.Microphthalmos

8.Morning-glory syndrome.

Radiological Finding

CT scan may show defect in the anterior cranial fossa. 3-dimensional coronal views can detect encephalocele easily. When associated with sphenoid bone dysplasia, enlargement of superior orbital fissure in plain film appear as "Bare orbit". CT scan may reveal an enlarged middle cranial fossa. The temporal lobe of brain may herniate through the whole posterior orbit. Enlargement of pituitary fossa and optic canal may be associated with these bony defects.22

Treatment

Surgical treatment is indicated in cases of exposure and lagophthalmos. Excision of small encephalocele through transfrontal craniotomy may be done. For a larger encephalocele, dural patching and bone grafting can be done.22

MICROPHTHALMOS WITH CYST

Microphthalmos with orbital cyst result from the failure of the choroidal fissure to close in embryo. This condition may be unilateral or bilateral. The presence of an orbital cyst may be beneficial for stimulating normal growth of the involved orbital bone and eyelid. The cyst is lined internally by gliotic

retina and externally by fibrous envelop. The cysts are usually located in inferior orbit and cause the lower lid to bulge. In almost all cases resulting eye is defective, smaller than normal and has an attached cystic mass at birth.23,24

The cyst may be smaller or larger than the eye. Cyst is bluish in color and translucent, and may displace the globe. In contrast congenital cystic eye results from failure of optic vesicle to involute. The eye is filled with both solid and cystic form of dysplastic neuroglial tissue.25 The cyst is connected to the brain by an astrocytic filled stalk, but it does not communicate to the anterior ventricle.

Both microphthalmos with cyst and congenital cystic eye should be distinguished from cystic teratoma and encephalocele by imaging studies.26

Management of microphthalmos with cyst and congenital cystic eye involves excision of the cysts and or globe along with abnormal neuroepithelial tissue.27 There has been a lot a work done on the use of sclerosing agents in such cysts. Ethanolamine oleate sclerotherapy may be an effective minimal intervention treatment option for cosmetic rehabilitation of patients with orbitopalpebral cyst associated with congenital microphthalmos with no visual potential.28,29

Each lesion is self centered and often an orbital implantation be placed and a prosthesis fitted to orbit in a satisfactory cosmetic effect. Sometimes removal of bone and reconstruction of the socket may be done.

MUCOCELE

Destruction of sinus ostium due to recurrent inflammation, trauma or intensive mucosal disease result in a mucous filled sinus or mucocele which can expand slowly to involve the orbital cavity. If the sinus is inflamed and the cyst contain pus or mucous, the term pyocele and mucopyocele respectively, apply. It may occur at any age, most common in between (40-70) years. Mucocele from frontalethmoidal sinus are most common. The enlargement of the mucocele is insidious, with proptosis and displacement of the globe being manifest in association with a palpable, smooth wall mass in the upper and inner quadrant of the orbit. Mucocele of the posterior orbit may present more insidiously with