Ocular surface squamous neoplasia in Northern Thailand: a 16-year review.

PURPOSE: To evaluate clinical characteristics, treatments, and outcomes in patients with ocular surface squamous neoplasia (OSSN) at a tertiary center in Northern Thailand. METHODS: Patients diagnosed with either corneal-conjunctival intraepithelial neoplasia (CIN) or squamous cell carcinoma (SCC) from May 2000 to December 2015, were recruited. The patients' demographics, symptoms, clinical characteristics, cytopathology, treatments, and outcomes were reviewed. RESULTS: Overall 171 eyes from 168 patients, 92 eyes were CIN and 79 eyes were SCC. Males were affected in 65.5%. The mean age was 58.8 ± 16.8 (29-99) years. In most cases (60.3%), the tumors were located at the limbus. The most common clinical characteristic was papilliform appearance (46.2%). Human immunodeficiency virus (HIV) infection was found in 37 (22.0%) patients with a mean age of 40.5 ± 7.7 years. The treatments and outcomes were evaluated in 136 eyes whose main initial treatment was wide excision with adjunctive cryotherapy (47.8%), followed by topical mitomycin C (30.9%). The mean follow-up time after treatment was 20.8 ± 2.2 (3-110) months and the recurrence occurred in 18 eyes (13.2%) during the follow-up period. The mean recurrence-free time (months) for CIN was significantly longer than that of SCC (81.3 ± 10.0 [95%CI 61.5 - 101.1] vs 33.2 ± 4.6 [95%CI 24.0 - 42.3], p = 0.030). SCC was the only significant risk factor that influences the recurrence of the tumors with the adjusted hazard ratio of 5.69 (p = 0.005). CONCLUSION: OSSN in Northern Thailand usually involved a limbal area and presented as a papilliform mass. HIV infection should be suspected in young patients. CIN had better outcomes after treatments than invasive SCC.

Role of impression cytology in diagnosis of ocular surface neoplasia.

PURPOSE: To compare the accuracy of impression cytology in the diagnosis of ocular surface neoplasia with tissue histology. METHODS: We reviewed the histories of patients diagnosed with ocular surface neoplasia at the Chiang Mai University Hospital. All patients underwent both impression cytology and tissue biopsy. We compared the results of both methods. RESULTS: There were 55 patients (33 men and 22 women), with an age range of 12-99 years (mean, 51 years). Twenty patients had lesions in the right eye and 35 had them in the left eye. The most common histologic report was conjunctival-corneal intraepithelial neoplasia (38.2%), followed by squamous cell carcinoma (34.5%), nonneoplastic changes of squamous epithelia (10.9%), squamous papilloma (7.3%), conjunctival nevi (7.3%), and malignant melanoma (1.8%). Compared with histologic findings, the positive and negative predictive accuracy of impression cytology was 97.4% and 52.9%, respectively. For squamous neoplasms, squamous cell carcinoma had the highest correlation with histology. The presence of dysplastic cells suggested malignancy. CONCLUSIONS: This study shows that impression cytology might have a promising role in diagnosing ocular surface neoplasia for its high positive predictive accuracy compared with tissue histology. However, a fair negative predictive accuracy indicates that impression cytology is a valuable screening technique, but it is not a "gold standard."