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ARTICLES |
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Year : 1978 | Volume
: 26
| Issue : 1 | Page : 49-50 |
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Episcleral osseous choristoma
KL Sheth, RN Mathur, JJ Sheth
Department of Ophthalmology, Medical College and S.S.G. Hospital, Baroda, India
Correspondence Address: K L Sheth Department of Ophthalmology, Medical College and S.S.G. Hospital, Baroda India
Source of Support: None, Conflict of Interest: None | Check |
PMID: 711279
How to cite this article: Sheth K L, Mathur R N, Sheth J J. Episcleral osseous choristoma. Indian J Ophthalmol 1978;26:49-50 |
Episcleral osseous choristoma is a rare lesion of conjunctiva and episclera characterised by a small solitary nodule of bone surrounded by fibrous connective tissue.
'Epibulbar osteoma' was the term used by Ballantyne to describe this rare lesion, but since this lesion is always in the episcleral tissue. Zimmermann preferred to say 'Episcleral' rather than `Epibulbar'[4]
The lesion is usually located in the upper temporal quadrant about 5 to 10 m.m. from the limbus. The size is usually small but varies from small `Pea' to that of an almond. Most of these tumours are present from birth and there have been no associated ocular anomalies in any of the cases reported in the literature.
The earliest report of this lesion was, put on record as far back as in the year 1863 by von Graefe[3], since then only 26 cases have been reported. And as far as we know not a single case is reported in Indian Journal. Because of this rarity we are tempted to report our case which we came across in February 1977.
Case report | | |
A young girl of 5, came to the O.P.D. with a small nodule in the upper temporal quadrant -about 9 m.m. away from the limbus, which was noted by the parents when the child was about 3 years. The lesion was non progressive and there were no other complains.
On examination | | |
A round nodule of about 4 m.m. diameter was situated on the upper temporal quadrant, 8 m.m. away from the limbus.
The colour of the nodule was yellowish white and was not surrounded by blood vessels. It was firm in consistency and was fixed to sclera.
The conjunctiva over it was free.
Except this nodule, the eye was normal externally.
Fundus showed no abnormality.
The provisional diagnosis was `probable dermoid'. The patient was admitted for excision of the nodule.
The excised nodule was sent for histopathological examination.
Histopathological report
Microscopic examination showed Haversian canals surrounded by mature compact bone.
It was microscopic examination which gave us the final diagnosis `Osseous choristoma'.
Discussion | | |
Hartride, Parsons and Duke Elder[2] believed this tumour as 'teratoma'; but according to definition teratoma is a true tumour or neoplasm comprised of multiple tissues of kinds foreign to the part in which it arises.
Of course the subscleral osseous choristoma contains bone which is foreign to the conjunctiva, but this satisfied only half the definition. In all the cases, reported so far, it was only bone and no other tissue was found.
It is also not the solid episcleral dermoid because of the following reasons.
1. About 30% of the epibulbar dermoids are associated with congenital anomaly of the eye or rest of the body.
2. None of the epibulbar dermoids reported so far has been found to contain bone, where as episcleral osteomas are composed entirely of mature compact bone with no epidermoid structures.
3. Almost all the cases of osseous choristoma reported so far were found in the upper temporal or temporal quadrant, while the dermoids may be situated in any quadrant, although the temporal quadrant is also site for dermoid.
According to Reese these[3] lesions represent an atavistic phenomenon since cartilage and even bone are normal constituents of the sclera of many lower vertebrates.
Summary | | |
A rare case of episcleral osseous choristoma is reported.
References | | |
1. | Ballanniyne, AJ., 1940, Ophthalmological, 99, 87. |
2. | Duke-Elder, W S , 1958, System of Ophthalmology St. Lonis, Mosby, V.I., 317. |
3. | Reese A.B., 1951, Tumours of the Eye, New York, Hoebar, p. 450. |
4. | Willis, R.A., 1948, Pathology of Tumours, St. Lovis Mosby, p. 940. |
[Figure - 1], [Figure - 2]
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