The differential diagnosis of localised amelanotic limbal lesions: a review of 162 consecutive excisions.

AIMS To report the distribution of histopathological diagnoses in patients who underwent excision of localised limbal lesions that were clinically suspected to be squamous neoplasia (intra-epithelial neoplasia or squamous cell carcinoma). METHODS 162 consecutive patients of a single ocular oncologist underwent an excisional biopsy between 1998 and 2009 for suspected squamous neoplasia. Histopathological reports were retrospectively reviewed. RESULTS The population comprised 122 males and 40 females. The mean age was 63.4±15.8 (range: 27-90). 138 (85.2%) lesions were identified as intraepithelial neoplasia (CIN), of which 34 (21.0%) were CIN I, 32 (19.8%) were CIN II and 72 (44.4%) were CIN III or squamous cell carcinoma in situ. In seven (4.3%) cases, the lesion was invasive squamous cell carcinoma. In two (1.2%) cases, the lesion was amelanotic malignant melanoma. In 16 (9.9%) cases, histopathology revealed a benign entity including lesions described as squamous papilloma, solar elastosis and epithelial hyperplasia, keratosis or reactive atypia. CONCLUSIONS In this population, for an experienced ocular oncologist, the misdiagnosis of localised limbal squamous neoplasia occurred in 10.5% of cases, with 5.5% of cases being malignant. This study highlights the importance of acquiring a clinical diagnosis before administering a topical chemotherapeutic agent.