Solitary keratoacanthoma of the conjunctiva: report of a case.

Keratoacanthoma characteristically occurs on the skin and is rarely found in the conjunctiva. We, herein, report a case of a healthy 41-year-old Thai woman presenting with a rapidly growing conjunctival mass. The tumor was excised to exclude squamous cell carcinoma. Histopathology revealed a cup shaped well-circumscribed proliferation of squamous cells, with a central keratin crater, consistent with a keratoacanthoma. On the literature review, only 12 cases have previously been reported in the English language. The mean age of presentation was 40.75 years, with a male preponderance. Presentation of a mass was mostly within 4 weeks after onset. History of foreign material getting into the eye was positive in 5 cases. All cases were successfully treated by excision, except for one case in which malignancy transformation was found, and enucleation was required eventually. Conjunctival keratoacanthoma is a rare disease. However, this lesion should be well recognized and not misinterpreted as malignancy. As far as we are aware, this is the first report of conjunctival keratoacanthoma from this region.