|Year : 2003 | Volume
| Issue : 1 | Page : 85-87
Myxoma of the orbit.
S Rambhatla, N Subramanian, JK Gangadhara Sundar, S Krishnakumar, J Biswas
Medical and Vision Research Foundation, Sankara Nethralaya, Chennai, India
Medical and Vision Research Foundation, Sankara Nethralaya, Chennai
Source of Support: None, Conflict of Interest: None
Myxomas are rare, benign neoplasms of mesenchymal origin that usually develop in soft tissues. As the clinical manifestations are non-specific, it is difficult to diagnose the tumour without biopsy and histopathological examination. We report a case of orbital myxoma with histopathological correlation.
Keywords: Orbit, myxoma, proptosis
|How to cite this article:|
Rambhatla S, Subramanian N, Gangadhara Sundar J K, Krishnakumar S, Biswas J. Myxoma of the orbit. Indian J Ophthalmol 2003;51:85-7
|How to cite this URL:|
Rambhatla S, Subramanian N, Gangadhara Sundar J K, Krishnakumar S, Biswas J. Myxoma of the orbit. Indian J Ophthalmol [serial online] 2003 [cited 2020 Apr 5];51:85-7. Available from: http://www.ijo.in/text.asp?2003/51/1/85/14729
A 52-year-old woman presented with complaints of protrusion of the left eye of 20 years' duration. She had noticed a recent aggravation over the past two years. Twenty years earlier she had been diagnosed with pseudotumour of the left orbit and was treated with oral prednisolone by her local ophthalmologist. The pain and redness subsided but the prominence persisted for the next 18 years. Two years ago she noticed an increase in prominence and was referred to us after a diagnosis of orbital tumour.
On examination her best-corrected visual acuity was 6/6:N6 in both eyes. Extraocular movements were full. Slitlamp examination of the anterior segment was unremarkable apart from an early posterior subcapsular cataract in both eyes. Intraocular pressure was normal in both eyes. Fundus examination by indirect ophthalmoscopy showed clear media, and 0.7 optic cup with a uniform healthy neuroretinal rim. The macula and retinal periphery were normal.
Orbital evaluation confirmed an axial proptosis of 8 mm (Hertel's exophthalmometry). Lagophthalmos or lid retraction, afferent pupillary defect were not present. The bony margins were intact and normal; no mass was felt on anterior orbital palpation. There was increased resistance to retropulsion. The proptosis was non-compressible, not reducible and non-pulsatile.
Ultrasonography of the left orbit showed a well-delineated cystic mass in the intraconal space with an echolucent internal structure and a single, high-reflective spike within it. The ocular muscles were distinct from the mass, and separate from the optic nerve. A diagnosis of orbital cysticercosis was suggested by the sonologist. CT scan of orbit showed a round well-circumscribed, isodense, minimally enhancing mass lesion. The mass was located in the retrobulbar lateral intraconal space causing superomedial displacement of the optic nerve. A small round calcification was seen within the mass [Figure - 1] a and b. The optic nerve and ocular muscles were normal. The radiologist suggested a diagnosis of cavernous haemangioma with phlebolith.
The patient underwent lateral orbitotomy, and a well-circumscribed grayish mass was delivered in toto. The mass was in close relation to the optic nerve and the lateral rectus muscle.
Gross examination revealed a capsulated lobular tumour measuring 21mm x 12 mm x10 mm. The tumour was soft in consistency. The cut section of the tumour had a glistening, gray-white appearance [Figure - 2]. Histopathological examination of the mass revealed a capsulated tumour composed of myxoid hypocellular material with scattered cells. The cells had small hyperchromatic pyknotic nuclei and scanty cytoplasm, with a stellate appearance. The vessels were very sparse. There was no cellular pleomorphism and there were no multinucleated giant cells. Collagen fibres were seen with fibroblastic cells in the periphery. Special stain for mucin by alcian blue was positive at a pH 2.5, confirming the acid mucopolysaccharide nature of the tumour [Figure - 3] a and b. The histopathological features were consistent with a diagnosis of myxoma.
After removal of the mass the pupil dilated; intravenous hydrocortisone infusion was immediately given. Fundus examination by indirect ophthalmoscopy showed a normal disc and vessels. In the early postoperative period the vision recorded 6/9 and the fundus appeared normal though the pupil remained in a mildly dilated state.
The patient returned for follow-up examination three months later with no protrusion of the eye and best corrected visual acuity of 6/6: N6 in both eyes. Ultrasound of the orbit did not show any mass lesion.
| Discussion|| |
Fuch in 1914 is credited with the first report of a myxoma of the orbit in a 40-year-old woman who had increasing proptosis of 7 years' duration. So far only 9 cases of myxoma of the orbit have been reported. ,,,,,,Myxomas are true neoplasms of primitive mesenchyme that do not metastasise. Soft tissue myxomas usually present clinically as painless masses. Growth is usually slow and expansive. There may occasionally a period of accelerated growth, due to myxoid degeneration in these tumours.
Myxomas are not highly vascular and usually radiolucent. They appear as smooth, rubbery, gray-white spherical masses with a gelatinous cut surface. The consistency may vary depending on the amount of fibrous tissue. They may appear encapsulated owing to compression and condensation of the surrounding tissues, but they lack a true capsule and are locally infiltrative. Microscopically, stellate or spindle-shaped cells with small, pyknotic nuclei are seen in an abundant myxoid or mucoid stroma rich in hyaluronidase.
Myxomas need differentiation from a spectrum of reactive and neoplastic processes that may show prominent myxoid degeneration, including nodular fasciitis, schwanomma and neurofibromas and malignant tumours such as myxoid chondrosarcoma and malignant fibrous histiocytoma. Unlike benign myxomas, these sarcomas display areas of increased cellularity, pleomorphism, mitotic activity, and a rich vascular network. Before confirming a diagnosis of myxoma any myxomatous tumour should have a thorough histologic evaluation to eliminate the possibility of a sarcomatous component. 
The tumour in our patient presented as a unilateral proptosis of 20 years' duration. There was a waxing and waning of the proptosis with some degree of response to systemic (oral) corticosteroids. The rapid progression of the lesion in the last two years could have been due to the myxoid degeneration in the tumour. It resembled a cystic lesion in ultrasonography and CT scan. The ultrasound features were suggestive of orbital cysticercosis considering the cystic lesion with hyperechoic reflective specks (suggestive of the scolex) and close approximation to the lateral rectus muscle. The CT scan with a well-circumscribed isodense minimally enhancing mass lesion raised the suspicion of a cavernous haemangioma with a phlebolith. Possible damage to the ciliary ganglion could explain the persistent mydriasis in the affected eye. Complete removal seems to be the treatment of choice.
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[Figure - 1], [Figure - 2], [Figure - 3]
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