|Year : 1987 | Volume
| Issue : 4 | Page : 214-215
Intra Orbital Osteoma - A Case Report
MRC Naidu, DR Reddy, PK Reddy, KVR Sastry, Kakarla Subbarao
|Date of Web Publication||20-Dec-2008|
Source of Support: None, Conflict of Interest: None
Osteoma which is totally within the orbit is rare One such case producing unilateral Proptosis is reported and the literature is briefly reviewed.
|How to cite this article:|
Naidu M, Reddy D R, Reddy P K, Sastry K, Subbarao K. Intra Orbital Osteoma - A Case Report. Indian J Ophthalmol 1987;35:214-5
|How to cite this URL:|
Naidu M, Reddy D R, Reddy P K, Sastry K, Subbarao K. Intra Orbital Osteoma - A Case Report. Indian J Ophthalmol [serial online] 1987 [cited 2020 Apr 7];35:214-5. Available from: http://www.ijo.in/text.asp?1987/35/4/214/26177
| Introduction|| |
The first case of Osteoma arising from the orbital bones was reported by Viega in 1586- It took another 130 years to report similar case by Louis in 1723  . Because of this extreme rarity, a case of Osteoma arising from the orbit producing proptosis is being reported.
| Case Report|| |
A 15 years old boy was admitted with progressive proptosis of left eye. Examination revealed that the left eye was pushed down and outwards Visual acuity and fundus examination were normal Ocular movements were restricted more so medially. A bony hardswelling could be palpated in the medial aspect of the left orbit which was smooth and non-tender.
Skiagram of the skull revealed hyperdense mass in the medial aspect of the left orbit with irregular margins [Figure 1]. There were areas of fluency. CT. scan confirmed the bony nature of the tumour which was pushing the eye ball and optic nerve laterally [Figure 2]. Patient was operated upon and the orbit was approached through a modified transfrontal craniotomy. The entire tumour was intra-orbital and medially it was found to be arising from the orbital process of the ethmoidal bone The ethmoid sinuses were not involved The tumour could be removed completely. The posterior and lateral aspects of the tumour were irregular and the optic nerve grooved it laterally. Post-operative course was uneventful.
The excised bony tumour had irregular surface except at one place where it was smooth. Cut section showed densely sclerotic periphery and part of the remaining mass was finely spongy [Figure 3]. Following decalcification, paraffin sections of 6 mm thickness were cut Part of the surface of the tumour was found to contain a lining of respiratory epithelium [Figure 4]. The presence of respiratory epithelium suggests that the osteoma originated in the sinuses though it was found to be exclusively intra orbital radiologically and also at surgery.
| Discussion|| |
As the literature consists of only case reports, some based only on radiological appearance without histopathologic examination, and also includes exostoses which are not true neoplasms, the actual incidence of this tumour is difficult to assess Majority of the osteomas reported had originated in the adjacent sinuses with intra orbital extension In the case under report the osteoma was entirely infra orbital without involvement of sinuses The respiratory epithelium which is seen over part of the surface is probably from the ethmoid sinus which got stripped off partially while the tumour was being removed The tumour was arising from the orbital process of the ethmoidal bone.
In the Mayoclinic series of 465 orbital tumours there were only 5 osteomas  . In a series of 300 cases of orbital tumours by Maroon and Kennerdell  , there was no case of osteoma, though the authors say that osteomas are the most common tumours of bone or cartilage affecting the bony orbit and forming 1 % of all orbital tumors.
Depending upon the proportions of bone and connective tissue within the tumour, gradation in the density of the roentgenographic shadows differ. On the radiological examination the ebur nated type is very opaque, while the spongiose type is less opaque and is more mottled due to more connective tissue content Histologically, the lamellae are arranged in whorls in the former, and fibroblasts separate the inter connecting lamellae in the latter. In the mixed type the central core consists of fibro-osseous tissue, surrounded by a hard ivory like exterior. This particular osteoma appears to be of the mixed type.
| References|| |
Henderson J.W. Orbital Tumours, 2d ed New York: Brian C Decker, 1980.
Maroon, J.C, Kennerdell, J. S, Tumours of the orbit, in Neurosurgery, Robert Wilkins & Setti Rangachary Eds, Mc Graw, NewYork 964-976, 1985.
[Figure 1], [Figure 2], [Figure 3], [Figure 4]