Impression Cytology of Pterygium

Abstract

The purpose of this study was to study the morphology and cytokeratin expression in the epithelia of pterygia. Impression cytology and immunohistochemical staining with antikeratin antibodies were performed in 32 eyes of 16 patients with pterygia. TUNEL stain and electron microscopy were also performed in surgical specimens ofpterygium. Squamous metaplasia-like epithelial cells were found in all specimens of impression cytology, especially in the head part. These specimens had positive immunostaining by antipancytokeratin antibodies, but not by anti-K12 AK2 mAb. Goblet cells were found around the area of these abnormal epithelial cells. TUNEL-positive cells were found in the epithelia of the pterygial head, but not in the body of pterygia and normal conjunctiva. The expressional patterns of keratin by these epithelial cells ofpterygia are consistent with the notion that they are derived from conjunctival epithelium and mimic the process of squamous metaplasia.

Increased oxidative DNA damage, 8-hydroxydeoxy- guanosine, in human pterygium

“…5,6,14 On the other hand, the epithelium of pterygium may display squamous metaplasia. 15 In addition, adjunctive alkylating antineoplastic agent or radiotherapy is usually required to prevent the high recurrent rate in the treatment of pterygium. 16,17 Furthermore, the presence of oncogenic viruses, 18 loss of heterozygosity, 19 and abnormal expression of p53 in pterygium tissues 20 suggest possible neoplastic nature of pterygium.…”

Role of Pre And Postoperative Topical Cyclosporine (0.05%) on Recurrence in Recurrent And Vascularised Pterygium

“…A stromal overgrowth of fibroblast and blood vessel is accompanied by an inflammatory cell infiltrate and abnormal extracellular matrix accumulation [3][4][5][6]. Although several hypotheses have been associated with its etiology, its pathology still remains to be explained.…”

Use of impression cytology for the detection of unsuspected ocular surface squamous neoplasia cells in pterygia

“…Bias was reduced by masking the cytologists and pathologists. Previous studies of IC samples obtained from pterygia surfaces have reported conjunctival squamous metaplasia and goblet cells without atypical cells (18)(19) . However, IC analysis of subclinical intraepithelial OSSN has already been described.…”

“…Thus, it is difficult to diagnose these patients based on clinical characteristics alone (15) . Impression cytology (IC), a method for the evaluation of superficial cell layers in the diagnosis (16) and treatment follow-up of several ocular surface tumors (17) , has exhibited squamous metaplasia with goblet cells in specimens obtained from pterygia (18)(19) . A graded series of ocular surface changes has been described throughout the bulbar conjunctiva, with the most advanced changes occurring directly over the pterygium surface, confirming that pterygium is indeed an ocular surface disorder (18) .…”