Histopathologic Characterization of Pterygia in the Bronx – 15 Year Evaluation

Abstract

Purpose : Several studies have reported ocular surface neoplasia and choristoma occurring within excised pterygium tissue. We sought to evaluate the histopathology of all pterygia excised in a diverse Bronx population.

Methods : We performed a retrospective chart review of demographic, clinical and histopathologic data of patients clinically diagnosed with pterygia who underwent pterygium surgery from January 2000 to December 2015. All atypical histopathology was reexamined using preserved specimens and utilizing special stains by one pathologist. Atypia was defined as dysplasia, neoplasia, choristoma and melanosis. Only patients with complete data were included. Statistical analysis was performed with Excel and SPSS software. Significance was set at p<0.05.

Results : We identified 672 eyes that underwent pterygium surgery. Of these cases, only 604 of the operated eyes among 531 patients had complete records and were included for analysis. 46% of cases were male (n=242) and 54% female (n=289). The mean age was 51.2 years (SD=13.5) with a median of 51 years (IQR=41-61). Males had a mean age of 51.3 years (SD=13.2), and females, 51.3 years (SD=13.8). There was neither a significant difference in number (p=0.39) nor age of presentation (p=0.99) between the genders. The racial distribution was: White 2%, Black 36.4%, Hispanic 0.5%, Asian 2.5%, American Indian/Alaskan 1.2% and other/unknown 57.4%. 268 (50.7%) patients identified as Hispanic ethnicity. 50% of cases were right eyes (n=302) and 50% left (n=301). Only 6.1% of analyzed cases were documented as recurrent pterygia. The majority (76.7%) of pterygia were nasal; 3.1% were temporal, 5.5% were bi-headed and 14.7% were of undocumented location. The mean size of excised tissue was 0.32 cm³ (SD=1.01) for nasal pterygia and 0.34 cm³ (SD=0.46) for temporal pterygia. On histopathology, 97.5% (n=589) were typical pterygia; 1.3% (n=8) had melanosis; 0.3% (n=2) showed squamous dysplasia and 0.8% (n=5) had underlying choristoma. No primary or secondary carcinomas were identified within a mean follow up time of 86.6 months (SD=107.06).

Conclusions : Our study shows that clinically diagnosed pterygia may manifest atypical tissue and underscores the need to perform histopathology of all excised pterygium. Documentation of histopathologic findings will help to unmask the true incidence of anomalous lesions presenting as benign pterygia and the populations at risk.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.