| ORIGINAL ARTICLE |
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|Year : 1991 | Volume : 39 | Issue : 4 | Page : 168-169 |
Neoplasms of the limbus
PP Sunderraj, Ravi K Viswanathan, R Balachander
Govt. Ophthalmic Hospital and Regional Institute of Ophthalmology, Madras, India
P P Sunderraj
17 Alagappa Lay-out, Pollachi, Tamil Nadu 642001
One hundred consecutively excised and histologically diagnosed limbal neoplasms were analyzed. Majority (56%) of the affected patients were less than 30 years old. Benign tumours (77%) outnumbered the malignancies. Dermoids (29%) and hyperplastic squamous epithelium or 'epidermalization' (26%) were the commonest benign neoplasms. Squamous cell carcinoma, including frank and non-invasive carcinoma (23%) was the most frequent malignant tumour. These observations were compared with previous Indian and Western studies and the implications discussed.
|How to cite this article: |
Sunderraj P P, Viswanathan RK, Balachander R. Neoplasms of the limbus. Indian J Ophthalmol 1991;39:168-9
| Introduction || || |
New growths are relatively common at the limbus, as in other parts of the body where there is a sharp differentiation of epithelium . Several studies have dealt with conjunctival tumours as a whole in both Indian  and Western  ophthalmic literature but only limited information is available regarding neoplasms arising from the limbus ,. Hence the following study was carried out to determine the frequency of various limbal tumours in South India.
| Material and methods || || |
This report is a retrospective analysis of the case records of the Department of Pathology of our hospital. These records pertain to the case history and histopathologic examination of 100 consecutively excised limbal tumours seen over a period of seven years. The excised specimens were microscopically examined after routine fixation and staining. Special staining techniques were used, where necessary, for precise diagnosis.
| Observations and discussion || || |
Majority (56%) of the affected persons were less than 30 years old [Table - 1]. There was no significant difference in sex distribution. Benign tumours (77%) were more than malignant and premaligant lesions [ Table 2] as in previous studies ,,,.
Of the individual neoplasms, dermoid (29%) was the tumour most frequently encountered at the limbus. Gogi (56%)2 and Das (34%)8 had the same experience unlike Western reports  where naevi (24%) outnumbered the dermoids (10%). Consistent with past reports ,,patients with dermoids usually presented for treatment before they were fifteen years old. Dermoids have been cited as the com monest benign ocular neoplasm in children . The presenting complaints were invariably cosmetic disfigurement due to the mass and/or ocular irritation due to the projecting hair. Majority of the dermoids were raised, solid, circumscribed, white and hairy lesions involving both the cornea and sclera. One of our patients had associated preauricular appendages, pretragal fistula and vertebral anomalies typical of the Goldenhar syndrome. These congenital tumours are due to a developmental error which results in the displacement of the primitive ectoderm during closure of the foetal clefts 
Hyperplastic squamous epithelium with or without dyskeratosis (26%) was the second most common limbal neoplasm. Clinically they appeared as fleshy growths of variable size which were usually diagnosed as squamous cell carcinoma. Ash and Wilder have pointed out that while 'epidermal ization' per se is harmless, it is an important precursor to the development of neoplasms, whether benign like papilloma or malignant like carcinoma. The frequency of this pathology was reported as 13% by Ash  but it is not clear why several previous Indian studies on conjunctiva  and limbal tumours do not mention this condition.
Squamous cell carcinoma comprised of 17% with frank malignancy and 6% with non-invasive carcinoma or carcinoma-in-situ including Bowen's disease. As already reported ,,,, this was the most frequent malignancy arising from the limbus and was commoner in middle aged men. Patients usually presented with fleshy, irregular growth in the limbus which was slowly increasing in size. It is well known that squamous cell carcinomas in this location are less malignant than elsewhere in the body  probably because of difficulty of spread over tough structures like the cornea and the sclera. Consequently, the growth remains superficial for a long time and localized excision is generally sufficient as curative treatment. However, two of our patients required enucleation because the growth had spread to involve both he cornea and sclera extensively. This may be because corneal involvement by the squamous cell carcinoma is more frequent in developing countries at presentation compared to Western countries, probably due to delays in consulting the ophthalmologist .
Inflammatory granuloma (8%) occurred less frequently in the limbus compared to the conjunctiva as a whole (22%) . These lesions were usually small, polypoid and friable with the tendency to be misdiagnosed clinically as a papilloma or rhinosporidiosis.
Causal factors are not known with certainly but could include trauma and foreign bodies like vegetable matter .
Papillomas (5%) were less common than the 7% sub 16% sub and 17%  already reported. These epithelial tumours appeared as small, mobile, pedunculated growths which did not involve the cornea or recur after simple excision. However, they are rarely capable of undergoing malignant transformation into squamous cell carcinoma .
Naevus occurred in 3% of our patients compared to 0% , and 12%  in previous Indian surveys. This is much less than the 24% sub observed in America probably due to differences in race and degree of skin pigmentation. Two of our three patients presented in the second decade of life with a relatively well circumscribed, elevated and darkly pigmented lesion. Though congenital in origin, naevi may manifest only later in life with increase in size or pigmentation occurring during puberty. This may be related to hormonal influence on melanogenesis. We did not observe malignant transformation in any naevus but though rare this is possible .
Apart from the above common neoplasms, others (7%) were rare and included one case each of an epithelial cyst, lipoma, fibroma, neurofibroma, angioma, lymphoma and spring catarrh.
| References || || |
|1. ||Ash J E, Wilder H C. Am.J.Ophthalmol 25: 926-932, 1942 |
|2. ||Gogi R, Nath K. Gogi R. Indian J. Ophthalmol. 28 : 171, 1981 |
|3. ||Zaidi N, Nath K, Gogi R. Indian J. Ophthalmol, 28 171, 1981 |
|4. ||Reddy S C, Sarma C S, Rao V V R, Banerjee S. Indian J. Ophthalmol. 31 : 658, 1983 |
|5. ||Sunder Raj P P. Pugalenthi N. Afro-Asian J. Ophthalmol. 6 : 16-19, 1987 |
|6. ||Ash J E. Am.J. Ophthalmol. 33 : 1203-19, 1950 |
|7. ||Reese A B. Tumours of the Eye. Hagerstown, Maryland. Harper and Row, 1979 |
|8. ||Das S P J. All India Ophthalmol Soc,. 14 : 83-86, 1966 |
|9. ||Sunder Raj P P Ravi K V., Rajastan J, Ophthalmol 12 : 13-17, 1987 |
|10. ||Greer C.H. Ocular pathology. London Blackwell scientific, 1979 |
Tables [Table - 1], [Table - 2]