Abstract
Purpose :
Pterygium is a common lesion of unknown etiology that affects the bulbar conjunctiva. Its prevalence in populations living near the equator suggests a link to UV exposure. There is no documented risk of malignant transformation, however concomitant disease is not rare and the exposure to sunlight indicates a patient at risk for malignancy.
The purpose of our study is to describe the histopathological features of resected pterygiums and to recognize patients at risk of conjunctival malignancy.
Methods :
Out of a total of 854 conjunctival biopsies, 235 were diagnosed as pterygium. The mean age of patients at the time of the surgery was 56 years old and there was a slight predominance of males (3:2 ratio).
150 cases of excised pterygium were subjected to histopathological analysis. H&E sections were digitalized using a Zeiss Axio Scan.Z1 and changes in the epithelium and substantia propria were recorded according to the thirteen pre-defined morphological features listed in Table I.
Results :
Histopathological findings are shown in Table I. Neovascularization, solar elastosis and stromal plaques are hallmark features of pterygium. Other findings, including the degree of inflammation may be attributed to the chronicity and extent of the lesion at the time it was excised.
In our series, 20.6% (31/150) showed mild to moderate dysplasia, a finding associated to ocular surface squamous neoplasia and 31.3% (47/150) showed melanocytic hyperplasia, which could represent primary acquired melanosis.
The results show a positive correlation between dysplasia and chronic inflammation (p=0.012) and an inverse correlation with epithelial atrophy (p=0.001) and neovascularisation (p=0.05). Similarly, a positive correlation is observed between goblet cell hyperplasia and melanocytic hyperplasia (p=0.02).
Conclusions :
Our findings show that pterygiums harbour epithelial and subepithelial changes that may have pre-malignant features. Early signs of ocular surface squamous neoplasia or primary acquired melanosis were identified in 51% of our patients. Whilst being on the benign side of the spectrum, these two entities are known for their potential progression to malignancy.
Finally, a recommendation should be made for all surgically excised pterygium be sent for histopathological diagnosis. Associated histopathological findings suggestive of risk of malignancy should be identified and reported in those patients.
This is a 2020 ARVO Annual Meeting abstract.