|Year : 2004 | Volume
| Issue : 3 | Page : 244-6
Orbital dermoid cyst with intracranial extension.
U Srivastava, V Dakwale, A Jain, M Singhal
Department of Ophthalmology, M G M Medical College, Indore, Madhya Pradesh, India
|Date of Submission||16-Jan-2003|
|Date of Acceptance||22-Jul-2003|
Department of Ophthalmology, M G M Medical College, Indore, Madhya Pradesh
Source of Support: None, Conflict of Interest: None
A case of dermoid cyst with intracranial extension in a 10-year-old boy is reported. Intracranial extension of dermoid is not very common.
Keywords: Dermoid cyst, orbital cyst, intracranial extension
|How to cite this article:|
Srivastava U, Dakwale V, Jain A, Singhal M. Orbital dermoid cyst with intracranial extension. Indian J Ophthalmol 2004;52:244
|How to cite this URL:|
Srivastava U, Dakwale V, Jain A, Singhal M. Orbital dermoid cyst with intracranial extension. Indian J Ophthalmol [serial online] 2004 [cited 2020 May 30];52:244. Available from: http://www.ijo.in/text.asp?2004/52/3/244/14580
Dermoid cyst accounts for about 3-9% of all orbital masses and 0.04 to 0.6% of primary intracranial tumours., In rare cases primary orbital dermoid cyst can extend into the anterior cranial fossa through a bone defect. We report here a case of dermoid cyst of orbit with intracranial extension.
| Case report|| |
A 10-year-boy presented with a slowly progressing, painless swelling involving the nasal side of the lower left eyelid. The patient probably complained of this 5 years earlier, but the parents thought to seek an opinion only at this point. There was no history of headache, seizures, nasal discharge, trauma or any other general ailment.
On examination there was a diffuse swelling at the nasal side of the lower lid measuring approximately 3 x 2 cm on left side, and the skin over the swelling appeared stretched [Figure - 1]. Palpation revealed the swelling to be soft, non-compressible, non-reducible and non-pulsatile. Orbital margins could not be palpated due to lower lid oedema and swelling. The pinhole visual acuity was 6/60 in the left eye. Ocular movements were restricted medially with 15 degrees exotropia. The anterior segment was within normal limits. Fundus examination showed optic disc pallor. The right eye had a visual acuity of 6/6 and the ocular examination including fundus was unremarkable. Systemic examination revealed no neurological deficit.
Laboratory investigations where as follows: Hb=12 gm%; total and differential count = 4500; polymorphs = 41; lymphocytes = 41; monocytes = 2; eosinophils = 2; blood sugar = 99 mg%; blood urea = 43 mg% and urine routine examination within normal limits.
The skiagrams of chest-PA view and skull lateral view were within normal limits. X-ray orbits - AP view demonstrated enlargement of left orbit with bony erosion of the left orbital roof. Ocular sonography with a 10 MHz linear probe showed a well defined homogenous mass along the medial orbital wall on the left side. Colour doppler did not show any abnormal flow signals. Subsequently contrast enhanced CT (CECT) scan of head, orbits and paranasal sinuses was done. This showed a large well marginated hypodense non-enhancing lesion of 4.9 x 4.0 x 1.9 cms size in the left fronto-basal area with near CSF attenuation values. This lesion was seen extending posteriorly up to the sella and anterior aspect of temporal lobe region, without causing any midline shift. A well defined bony defect in the medial portion of the left orbital roof just adjacent to the cribriform plate was also seen through which this mass lesion (size = 6.1 x 1.6 x 2.1 cms) extended into the medial extraconal compartment of the left orbit causing lateral and inferior displacement of the globe and medial rectus muscle and compressing the optic nerve [Figure - 2]. Both the maxillary sinuses, sphenoid sinuses and ethmoidal air cells on the right side were clear. However, on the left side a soft tissue haze was seen in ethmoidal air cells. Bilateral ostemeatal complexes were normal.
Considering the clinical and radiological findings, the possibility of a benign lesion was considered with differential diagnosis of dermoid cyst, epidermoid cyst, arachnoid cyst and other non-neoplastic non-inflammatory cysts.
Subsequently the patient was operated upon and frontal osteoplastic craniotomy with transfrontal ethmoidectomy and medial orbitotomy was done in the same sitting. Dura was opened with the base at midline and the frontal lobe retracted. At the subfrontal area, a large thin-walled mass was seen extending into the left orbit through a bony defect adjacent to the cribriform plate. As it was not possible to resect the mass en bloc , it was ligated at the site of orbital roof bony defect and excised without spilling its contents [Figure - 3]. Bony defect in roof of left orbit was reconstructed with temporalis fascia graft and bony chips. The orbital portion of the mass was resected by transfrontal ethmoidectomy and medial orbitotomy as it was in relation to the nasal side of the orbit.
Histopathological examination of the resected mass showed stromal fragments, sebaceous glands, and fibro-fatty tissue with infiltration by chronic inflammatory cells spread around blood vessels. The section also showed keratin material with some brain tissue consistent with dermoid cyst [Figure - 4].
Postoperative recovery was uneventful. There was no CSF leak or neurological deficit because the mass positioned only in relation to the frontal lobe. The patient improved cosmetically with correction of exotropia [Figure - 5] but visual acuity did not improve due to optic atrophy. The patient is under regular follow-up with no fresh complaints or signs of recurrence.
| Discussion|| |
There are a variety of cystic and cyst-like lesions which involve the orbit in paediatric patients. The developmental orbital cysts include choristoma (epidermoid, dermoid, dermolipoma), teratoma, the congenital cystic eye, and colobomatous cyst.
Dermoid cyst is an ectodermal inclusion cyst which may occur anywhere in the body but its occurence in orbit and intracranial sites is relatively rare. Approximately 50% of tumours that involve the head are found in or adjacent to the orbit. The most frequent site of origin is the supero-temporal quadrant or orbit, and the parasellar and fronto-basal region are the most common intracranial sites., Dermoid cyst gradually increases in size through epithelial desquamation and glandular secretions. Malignant transformation is rarely seen.
Clinical presentation of orbital or intracranial dermoid cysts depends upon location, size and associated abnormalities of cyst. Orbital dermoid cyst located superficially in and around orbit presents as a subcutaneous or subconjunctival discrete well circumscribed swelling in childhood. Larger cysts that abut the globe or cysts that are located deep in the orbit may displace the globe and can compress the optic nerve and extraocular muscles leading to changes in vision, pupil irregularities, diplopia, strabismus, choroidal folds, optic disc oedema, optic atrophy, orbital congestion, globe displacement, proptosis, lid retraction of bleharoptosis. Uncomplicated intracranial dermoids present with headaches and seizures. In case of rupture of intracranial dermoid cyst a granulomatous inflammatory reaction is incited leading to chemical meningitis, seizures, vasopasm with infarctions and death. ,,
Pathologically dermoid cysts are well-defined lobulated masses containing thick, viscous oily fluid and cholesterol derived from decomposed epithelial cells. Dermal appendages like hairs, sebaceous and sweat glands are also seen.,
Imaging in dermoid cyst are valuable in diagnosis and characterisation of benign lesion and to demonstrate their intraorbital and intracranial extension. On CECT scan dermoid cyst shows a round, well-delineated, uniformly hypodense lesion with density ranging from that of CSF to fat. Capsular calcification is common and enhancement following intravenous contrast is not very frequently seen.,,
The various differential diagnoses of dermoid cyst are epidermoid cyst, arachnoid cyst and various non-neoplastic non-inflammatory developmental and acquired cysts.,, Epidermoid cyst can not be distinguished clinically from dermoid cyst. On CECT epidermoid cysts appear as low density (like CSF) mass lesion with occasional peripheral enhancement and calcification is highly uncommon.,, Arachnoid cyst on imaging too closely mimicks dermoid and epidermoid cyst, though the clinical presentation helps in distinguishing it.
Treatment of dermoid cyst is surgical en bloc excision, which is indicated for cosmetic purposes, confirmation of diagnosis, to relieve symptoms created by mass in periorbital region and to prevent complications in cases of intracranial extension. Complete surgical excision with intact capsule is done to prevent dissemination of the contents which otherwise can incite an acute inflammatory response. This is also to avoid deposition of cells that could form a new cyst at the operative site.,
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[Figure - 1], [Figure - 2], [Figure - 3], [Figure - 4], [Figure - 5]