Purpose
Pinguecula and pterygium (P/PT) are frequent, surgically removed conjunctival lesions strongly related to sunlight exposure. Ocular surface squamous neoplasia (OSSN) represents a broad spectrum of lesions starting as dysplasia and evolving into squamous cell carcinoma of the conjunctiva. The incidence of OSSN features in P/PT has been described in some high ultraviolet (UV) light exposure areas, including Sydney, Australia (5%) and Florida, USA (1.8%). The aim of this study is to determine the incidence of unsuspected OSSN and melanocytic lesions (ML) in P/PT in a low UV area (Montreal, Quebec, Canada).
Methods
A retrospective study of all cases received between 1993 and 2013 with a clinical diagnosis of P/PT from the Henry C. Witelson Ocular Pathology Lab, McGill University, Montreal, Quebec, Canada was performed. Demographic data were retrieved from histopathological request forms. Identified OSSN and ML in P/PT were classified accordingly to the Armed Forces Institute of Pathology (AFIP) recommendations.
Results
Two hundred and seventeen cases were diagnosed clinically as PT (91.13%) and 21 as P (9.87%); 56.54% of all P/PT patients were male. The average age at diagnosis was 53.4±15.54 years. The overall incidence of OSSN in these P/PT cases was 6.65% (P: 19.04% PT: 5.55%); 56.25% of this cohort were female. The average age of patients with P/PT and OSSN was similar to non-OSSN P/PT patients (P>0.05). The OSSN were diagnosed as conjunctival intraepithelial neoplasia (CIN) I (68.75%), CIN II (12.5%), CIN III (12.5%), and actinic keratosis (6.25%). ML included one primary acquired melanosis without atypia and one with mild atypia (a 41-year old woman and a 60-year old male, respectively).
Conclusions
We reviewed the incidence of OSSN and ML in P/PT from a single center in Canada and found a relatively high association of OSSN with P. Most epithelial P/PT lesions were CIN I and age was not a significant demographic risk factor for the development of OSSN in P/PT. Our relatively high rate of dysplasia in a low UV index area challenges the main cause of this disease in our population, a hypothesis that should be evaluated in future studies. We suggest that all P/PT samples should be submitted to pathology for review.
Keywords: 474 conjunctiva •
463 clinical (human) or epidemiologic studies: prevalence/incidence •
744 tumors