Seminars in Ophthalmology, 21 :207-211, 2006 Copyright © lnforma Healthcare

informa healthcare

ISSN: 0882-0538 DOl: 10.1080/08820530500353963

Rakesh Ahuja and Nathalie F. Azar Department of Pediatric Ophthalmology & Strabismus, Massachusetts Eye and Ear Infirmary, Boston, MA, USA

Address correspondence to Rakesh Ahuja, MD, 243 Charles St., Boston, MA 02114, USA. E-mail: rakesh_ahuja@ meei.harvard.edu

Orbital Dermoids in Children

ABSTRACT Orbital dermoid cysts are benign congenital choristomas. They

are common in pediatric population, developing adjacent to suture lines, most commonly located in antero-lateral fronto-zygomatic suture, and are slowly

progressive. Complete surgical excision without rupture of cyst is the standard

of care. Deep orbital cysts cause proptosis, require imaging, and may present a surgical challenge with a difficult approach. Rupture of the cyst leads to severe

inflammatory reaction in surrounding tissues. Overall prognosis remains good with isolated reports of malignancy masquerading as dermoid cysts.

KEYWORDS

INTRODUCTION

Dermoid cysts in children are congenital developmental abnormalities re­sulting from inclusion of ectodermal elements during closure of the neural tube adjacent to fetal suture lines. They are the most common orbital tumors in children. They are usually found near the lateral canthus at the temporal fronto­zygomatic suture above the superior orbital margin. The second most common site is the superomedial orbital rim. The superficial cyst is sm-all when first seen but may enlarge with age. Deep orbital dermoid cysts usually present later. They are most commonly found in teen or adults and present with proptosis. Inflammation occurs due to cyst leakage or rupture.

INCIDENCE

Demoid cysts represent 3 to 9% of orbital tumors. The incidence of various orbital tumors in children varies in different studies (Table 1). Orbital dermoids are among the most common benign lesions, along with vascular tumors and inflammatory lesions. In the pediatric population (upto age 18), dermoid cystic lesions are seen in as low as 1.6% (Crawford et a!., 1983) to as high as 52% (Shields et a!., 1986) of diagnosed orbital tumors. Studies including both clini­cally diagnosed and biopsied cases showed lesser incidence of cystic lesions as compared to studies including only biopsied cases.

PATHOLOGY

Dermoid cysts are developmental abnormalities or choristomas. The der­moid cyst is lined by cutaneous epithelium that rests on dermal tissues con­taining skin appendages and may have pedicle attachments to the periorbita. Gross pathological appearance of an excised orbital dermoid shows hair follicles

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TABLE 1 Comparison of Incidence of Orbital Dermoid Cysts Among Benign Orbital Tumors in Children

Iliff & Green, Crawford et al., 1978 1983

Total benign orbital tumors 174 572 Dermoid Cysts 52 6 Percentage 29.8% 1.6%

and sebaceous material lumped together. Keratin and lipid debris fill the lumen. Histologically, the cyst wall is lined by keratinizing, stratified squamous epithelium containing hair follicles, sebaceous and sweat glands and keratin. The cyst contents include white sebaceous­like material secreted by the epithelial lining, along with combination of hair, oily material, hemorrhagic fluid and cholestrin crystals.

Isolated case reports Qones et al., 1935; Wright et al., 1977) show squamous cell carcinoma developing in or­bital dermoid cysts. These warrant that a thorough study of the wall lining be done to rule out malignancy.

CLINICAL FEATURES

Dermoid cysts of the orbit are divided into superfi­cial and deep types, with the superficial type presenting early at around 1-3 years of age. They are present at birth and grow slowly. They may be discovered acci­dentally by parents, during washing of the face of the child. However, a cyst may not be apparent until later in adult life.

Anterior orbital dermoid cysts have consistent anatomic location and physical findings that allows for their identification with a high degree of accuracy. They show adnexal structures as well as epidermal compo­nents. They present as a painless, smooth, firm, mo­bile mass in the upper eyelid anterior to the fronto­zygomatic suture. They do not displace the eye at the time of the initial presentation. Occasionally the cyst may extend into the orbit and creating a mass effect. Imaging studies are needed to confirm localization.

Deep orbital dermoid cysts may not be detected un­til teenage or later in adult life. They arise from the orbital bony suture in a similar manner to the anterior dermoid cysts. They present most commonly with prop­tosis and imaging studies are required for localizing the mass lesion. As the epidermal lining continues its secre­tory activity, the cyst enlarges and areas ofbony erosion may appear and enlarge. The erosion may result in lo­cal deformity and may lead to generalized enlargement

R. Ahuja and N. F. Azar

Shields et al., Rootman et al., Kodsi et al., Katowitz et al., 1986 1988 1994 1996

250 241 340 243 115 27 65 71

46% 11.2% 19.1% 29.2%

of the orbit. Occasionally, bony erosion may progress through the lateral orbital wall, with the dermoid tak­ing an hourglass shape. Bone erosion may progress to extend intracranially and involve dural exposure.

Ultrasonography is helpful for localizing anterior and mid-orbit disease and is a cost-effective screen­ing tool (Char et al., 1982). Computed tomography (CT) has the ability to distinguish both normal and abnormal structures of various tissue densities. This has contributed to very low false positive and false nega­tive rates. CT scanning may show internal calcification. Bony excavation, molding and intracranial extension may be seen on CT scan imaging.

Computerized tomography and magnetic resonance imaging help accurately measure dermoid cyst location, size, extension, differentiate cystic from solid lesions, identify cyst type and help in planning management approach for difficult cases. In a 20-year review of com­puted tomography of 160 cases of orbital dermoids, Chawda et al. (1999) reported that 69% (111/160) were found at lateral aspect of the orbit, 85% had adjacent bone changes and 14% had calcification.

DIFFERENTIAL DIAGNOSIS

A superficial dermoid cyst can be diagnosed clini­cally by the typical presentation of a non-tender, mo­bile mass at the outer orbital rim in a young child. How­ever, an orbital mass with inflammation may be the presenting sign of a ruptured dermoid. Orbital celluli­tis, abcess parasitic cysts and pseudotumor may present with similar orbital signs and need to be differenti­ated from orbital dermoids. There are reported cases of congenital frontotemporal dermoid cyst presenting as a cutaneous fistula (Scolozzi et al., 2005; Honig et al., 1998). Occasionally, these dermoid cysts may have intracranial extension (Niederhagen et al., 1998). Orbital imaging using computerized tomographic (CT) scanning (Song et al., 1990) and magnetic resonance imaging (MRI) (Song et al., 1994) help differentiate cases of orbital tumors with inflammation, including

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TABLE 2 Differential Diagnosis of Orbital Dermoid Cyst

A. Orbital cysts: 1. Dermoid or epidermoid tumor 2. Pseudotumor 3. Mucocele 4. Lymphoma 5. Aneurysmal bone cyst 6. Lipodermoid 7. Epithelial lacrimal gland tumor 8. Dentigerous cyst 9. Teratomatous cyst

B. Inflammatory parasitic cysts 1. Echinococcal cyst 2. Cysticercosis

C. Noncystic orbital lesions with cystic component 1. Adenoid cystic carcinoma 2. Rhabdomyosarcoma 3. Lymphangioma 4. Squamous cell carcinoma 5. Orbital Abcess 6. Meningocele 7 Others

pseudotumor (Shields et al). CT scanning may show a soft tissue mass with a round to ovoid shape, with pos­sible bony fossa formation, bony expansion and some­times bone sclerosis. MRI can help delineate the full extent of the mass and may be quite useful for deep or­bital cysts which present as difficult surgical cases (Song et al., 1994). It is important to remember that malignant tumors may masquerade as orbital dermoid cysts. Table 2 lists the various differential diagnoses for orbital der­moid cysts.

SURGICAL lREATMENT

Complete surgical excision without rupture is the treatment of choice and standard of care. Classically, general anesthesia is required for these surgeries. The anterior cysts can be approached by a curved incision to the skin, parallel to the orbital rim over the mass. The mass is found anterior to the orbital septum. Blunt dissection should be done to free the dermoid from sur­rounding adhesions, taking care not to rupture the cyst. Pedicle attached to periosteum should be cut. Com­plete removal of intact cyst is mandatory and cura­tive. Any rupture or cut in wall of cyst may lead to extensive inflammation in the surrounding area. Cry­oprobe use may help seal a small rupture and deliver the cyst intact. In case of inadvertent rupture, profuse saline irrigation is recommended. Hemostasis should

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be maintained at all times with generous use of cautery. Closure is done in layers with absorbable sutures, us­ing 6-0 vicryl for deep closure and 4-0/5-0 silk for skin closure.

Guerrissi et al. (2004) have described endoscope as­sisted surgery in three steps: hair line incision, exposure of the cyst and cyst removal. Using local anaesthesia, 18 patients were operated using endoscopic technique with minimal occult scar and excellent post-operative outcome. Out of these 18 patients, 90% remained with­out recurrence at 2 years of follow-up.

Deep orbital cysts are difficult to approach and imag­ing studies should be used to prepare a surgical plan. The surgical goal remains complete excision and re­moval without rupturing the cyst, as also avoiding in­jury to delicate orbital contents, including the ocular tissues, vessels and nerves. They may present a surgi­cal challenge to the surgeon. For deep orbital cysts, the approach can be supero-nasal orbitotomy or more commonly lateral orbitotomy. A large majority of pos­terior orbital cysts are located in the upper temporal orbit and hence, postero-lateral orbitotomy is the rec­ommended approach (Carta et al., 1998). They report 8 cases with posterior intraconal space orbital tumors using postero-lateral approach through a small open­ing on the orbital and temporal portions of the greater wing of the sphenoid. The lesser sphenoidal wing, the orbital plate of the frontal bone and the lateral rim of the orbit being maintained intact. This technique allowed adequate exposure of the orbital apex and successful re­moval of the tumors. On histological examination these tumors included four cavernomas, one dermoid cyst, a lymphoma, a hemangiopericytoma and a metastatic melanoma.

Intracranial extension of dermoid cyst requires a multi-disciplinary approach with head and neck sur­geons and neurosurgeons. Gabibov et al. (1989) report transcranial approach on 12 cases with dermoid cysts of the orbit spreading into the cranial cavity. Orbital roof defect with extension to the lateral wall was present in these 8 patients and cyst capsule adhesion with the dura mater and orbital periosteum were present. They recommend use of an operative microscope and mi­crosurgical instruments for enhanced visualization and control over surgery. In their series, the dermoid cysts were removed without injury to the dura mater and orbital periosteum with good functional and cosmetic results (Gabibov et al., 1989).

Pediatric Dermoid Cysts

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COMPLICATIONS

Orbital dermoid cyst may cause local complications due to mass effect. Giant orbital cysts may cause lo­cal deformity of the bone and ocular motility prob­lems (Reim et a!., 1975). Perinatally ruptured dermoid cyst has been reported as presenting with congenital oculomotor palsy (Coevoet et a!., 2000) . Orbital der­moid cyst may be located within lateral rectus muscle (Howard eta!., 1994) and can clinically mimick Duane's syndrome type II (Gatzonis et a!. , 2002). Proptosis may be seen with slowly developing deep orbital dermoids . Cutaneous fistula due to dermoid cyst can present as a discharging sinus (Honig et a!. , 1998; Scolozzi et a!., 2005 ; Wang et a!. , 1983) and may become infected (Wells et a!., 2004). Lacrimal drainage pathway may be involved by orbital dermoid tumor (Hurwitz et a!. , 1982).

Complications may occur during surgical removal of the cyst. Rupture of dermoid cyst is the main com­plication if adequate care is not taken for localization and freeing up the cyst from its attachments to adja­cent structures. l~jury to adjacent orbital tissues dur­ing surgery can produce functional defects. Patient may show transient weakness oflateral rectus muscle due to surgical manipulation with lateral orbitotomy, which may subside in few months. Post-surgical hemorrhage may require re-surgery to control bleeding. Optic nerve damage may be inadvertent and a check on pupillary reaction helps avoid undue traction on globe and optic nerve manipulation in deep orbital tumors. Other rare complications include superior oblique palsy, which may occur with dermoid cyst impacting the region of the trochlea (Atilla et a!. , 2000). The orbital cysts may become infected (Ayache eta!., 2003) and present with periorbital cellulitis in young child, requiring a cranio­facial approach (Posnick et a!., 1994).

SUMMARY AND CONCLUSION

Superficial orbital dermoid cysts are most common orbital tumors in children and usually have a typical pre­sentation. Surgical removal of in tact cyst has an excel­lent visual and cosmetic prognosis in such cases. Deep orbital dermoid cysts present later in life and are more complex to diagnose and treat. They require radiologi­cal imaging for planning surgical approach and may be difficult to remove. Higher risk of injury to orbital and ocular tissues exists with their surgery.

R. Ahuja and N. F. Azar

REFERENCES At illa H, Erkam N, Gunduz K, Guna lp I. Superior ob lique muscle palsy

in a patient with orbital dermoid cyst. J Aapos 2000; 4(5):31 1-2.

Bickler-Bluth ME, Custer PL, Smith ME. Giant dermoid cyst of the orbit. Arch Ophthalmol 1987; 1 05(1 0): 1434-5.

Bonavolonta G, Tranfa F, deConcil iis C. et al. Dermoid cysts: 16 year survey. Ophthalm Plast Reconstr Surg 1995; 11 :187-92.

Borodic, G.E. 1994. Cystic lesions of the orbit. In: Albert, D.M. and Jako­biec, FA., eds. Principles and Practice of Ophthalmology 1895-1904. Philadelphia: WB Saunders.

Ca rta F, Siccardi D, Cossu M, et al. Remova l of tumours of the orbita l apex via a postero-lateral orbitotomy. J Neurosurg Sci 1998; 42(4): 185-88.

Crawford, J.S. Diseases of the Orbit. 1983. In J. S. Crawford, J. D. Morin (eds.), The Eye in Childhood 36 1-394. New York: Grune & Stratton.

Emerick GT, Sh ields CL, Shields JA, et al. Chewing-induced visual im­pa irment f rom a dumbbel l dermoid cyst. Ophthal Plast Reconstr Surg1997; 13(1):57-6 1

Gabibov GA, Sokolova ON, Cherekaev VA, et al. Dermoid cysts of the orbit spreading into the cranial cavity. Zh Vopr Neirokhir lm N N Burdenko 1989(5):49-5 1.

Grove AS, Jr. Giant dermoid cysts of the orbit. Ophthalmology 1979; 86(8) 151 3-20.

Honig JF. A de novo discharging sinus of the f ronto-orbital suture: a rare presentat ion of a dermoid cyst. J Craniofac Surg 1998; 9(6): 536-38.

Iliff, WJ, Green, WR. 1978 Orb ital t umors in children. In F. A. Jakobiec (ed.) Ocular and Adnexal Tumors (669-684)). Birmingham, AL: Aes­culapis Publishing Company.

Kronish JA, Dortzbach, RK. Upper eyelid crease su rgical approach to der­moid and epidermoid cysts in children. Arch Ophthalmol 1988; 106:1625-27.

Lane CM, Ehrlich WW, Wright JE. Orbita l dermoid cyst. Eye 1987 1 (Pt 4); 504- 11

Leonardo D, Shields CL, Shields JA, Nelson LB. Recurrent giant orbital dermoid of infancy. J Pediatr Ophthalmol Strabismus1994; 31 (1 ): 50-2.

Meyer DR, Lessner AM, Yeatts RP, et al. Primary temporal fossa dermoid cysts. Ophthalmology 1999; 106:342-49.

Nicholson DH, Green WR. 1981. Pediatric Ocular Tumors New York: Mas­son.

Niederhagen B, Reich RH, Zentner J. Temporal dermoid with intracra­nial extension: report of a case. J Oral Maxillofac Surg 1998; 56(11) 1352-54.

Ohtsuka K, Hashimoto M , Suzuki Y. A review of 244 orbital tumors in Japanese patients du ri ng a 21-year period: origins and locations. Jpn J Ophthalmol 2005; 49(1 ):49-55.

Panton RW, Sugar J. Excis ion of limba l dermoids. Ophthalmic Surg 199 1; 22:85-9.

Pollard ZF, Calhoun J. Deep orb ital dermoid with drai ning sinus. Am J Ophthalmol. 1975; 79(2):3 10-3.

Re im M, Freund J, Wegei-Lussen L. Giant dermoid cyst of orbit caus­ing disturbance of ocu lar moti lity. Mod Probl Ophthalmol 1975; 14:372-6.

Ruszkowski A, Caouette-Laberge L, Bortoluzzi P, Egerszegi EP. Superior eyel id incision: an alternative approach for frontozygomatic der­moid cyst excision. Ann Plast Surg 2000; 44(6):59 1-4: discussion 4-5.

Sathananthan N, Moseley IF, Rose GE, Wright JE. The frequency and clini­ca l significance of bone involvement in outer canthus dermoid cysts. Br J Ophthalmol 1993; 77:89

Scolozzi P, Lombardi T, Jaques B. Congen ita l in t racran ial fron totemporal dermoid cyst presenting as a cutaneous fistu la. Head Neck 2005: Feb 14.

Sherman RP, Rootman J, LaPointe JS. Orbita l dermoids: Clinical presenta­tion and management. Br J Ophthalmol 1984 ; 68:642-52.

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Sh ields JA, Augsburger JJ, Donoso LA. Orbital dermoid cyst of conjunctival origin. Am J Ophthalmol1986; 1 01(6):726-9

Sh ields JA, Bakewel l B, Augsburger JJ, et al. Space-occupying orbital masses in ch ildren. Ophthalmology 1986; 93:379-84.

Shields JA, Kaden IH, Eagle RC, et al. Orbital dermoid cysts: Clinico­pathologic corre lations, classification, and management. The 1997 Josephine E. Schueler Lectu re. Ophthalm Plast Reconstr Surg 1997; 13:265-76.

Shields JA, Kaden IH, Eagle RC, Jr., Shields CL. Orbital dermoid cysts: cli nicopatholog ic correlations, classification, and management. The 1997 Josephine E. Schueler Lectu re. Ophthal Plast Reconstr Surg 1997; 13(4)265-76

Shields JA, Shields CL, Christian C, Eagle RC, Jr. Orbital nodular fasci­itis simulating a dermoid cyst in an 8-month-old child. Case re­port and review of the literature. Ophthal Plast Reconstr Surg 2001; 17(2) 144-8.

Shields JA, Shields CL, Eagle RC, Jr., et al. Adenoid cystic carci noma of the lacrimal gland simulating a dermoid cyst in a 9-year-old boy. Arch Ophthalmol1998; 116(12):1673-6.

Shields JA, Sh ields CL, Scartozzi R. Survey of 1264 patients with orbital tumors and simu lating lesions: The 2002 Montgomery Lecture, part 1. Ophthalmology 2004; 111 (5):997-08.

211

Shields JA, Shields CL. Orbital cysts of chi ldhood-classification, clinical features, and management. Surv Ophthalmol2004; 49(3):28 1-99.

Sobel OF, Kel ly W, Kjos BO, et al. MR imaging of orbital and ocular disease. AJNR Am J Neuroradiol 1985; 6(2) 259-64.

Song GX. CT scanning in the diagnosis and treatment of intraorbital der­moid cyst. Zhonghua Yan Ke Za Zhi 1990; 26(6):343-5.

Song GX, Tian WF, Xiao LH. Magnetic resonance imaging in 80 cases of orbital tumors. Zhonghua Yan Ke Za Zhi 1994; 30(6):423-6.

West JA, Drewe RH, McNab AA. Atypical choristomatous cysts of the orbit. Aust N Z J Ophthalmol 1997; 25(2): 117-23.

W il kins RB, Byrd WA. lntraconal dermoid cyst. A case report. Ophthal Plast Reconstr Surg 1986; 2(2):83-7.

W ilson ME, Buckley EG, Kivli, JG, et al. 200 1-2001. Basic and Clin ica l Science Course, Section 6. San Francisco: American Academy of Ophthalmology.

Wolfley DE. The lid crease approach to the superomedial orbit. Ophthalmic Surg 1985; 16(1 0):652- 6.

Yeatts RP. 1997. Cystic tumors. In: Duane's Clinical Ophthalmology, re­vised edition. Tasman W, Jaeger EA, eds. Philadelphia: Lippincott­Raven: 1997.

Youssefi B. Orbital tumors in chi ldren. J Ped Ophthalmol Strab 1969; 6: 177-81 .

Pediatric Dermoid Cysts