Squamous cell dysplasia and carcinoma of the conjunctiva. A nationwide, retrospective, epidemiological study of Danish patients

PURPOSE: To investigate the epidemiology of squamous cell dysplasia and carcinoma of the conjunctiva in Denmark.

METHODS: Review of the histopathological case reports at the Eye Pathology Institute (EPI), University of Copenhagen, and the National Danish Pathology Bank from 1980 to 2011. Information regarding distribution of age and sex, localization, earlier pathology, comorbidity and recurrence of the condition was registered. The Cause of Death Registry at Statens Serum Institut was used to obtain information regarding cause of death.

RESULTS: A total of 143 cases were identified. Ninety-five (61%) had epithelial dysplasia, 19 (13%) had carcinoma in situ, and 29 (20%) had squamous cell carcinoma. A significantly higher proportion of men were found. The median age at diagnosis was 65 years. The risk of recurrence was 10.0% [95% confidence interval (CI): 5.0-15.0] after 1 year and 17.2% (95% CI: 10.8-23.7) after 5 years. The lesions were most often localized to the corneal limbus. In our records, one patient had a lymph node metastasis and the disease necessitated enucleation in two patients. No patients had died from squamous cell carcinoma of the conjunctiva.

CONCLUSION: Overall, our data are in agreement with the results of previous studies in Northern, high-latitude countries. There is a low incidence rate; the lesions are predominantly seen in men in their seventh decade and localized to the corneal limbus. The risk of recurrence is high, and the benign lesions have potential to progress to frank carcinoma.