title: Ophthalmic pterygium: a stem cell disorder with premalignant features.
abstract: Pterygia are common ocular surface lesions thought to originate from limbal stem cells altered by chronic UV exposure. Traditionally regarded as a degenerative condition, pterygia also display tumor-like features, such as a propensity to invade normal tissue and high recurrence rates following resection, and may coexist with secondary premalignant lesions. This study was initiated to determine the rate of concurrent ocular surface diseases in patients with pterygia recruited from the practice of a single surgeon operating in a Sydney metropolitan hospital. One hundred pterygium specimens were histopathologically reviewed and selected cases were immunohistochemically assessed to confirm diagnosis. Along with previously documented typical features including epithelial proliferation, goblet cell hyperplasia, angiogenesis, inflammation, elastosis, stromal plaques, and Bowman's membrane dissolution, we identified five cases of ocular surface squamous neoplasia, six cases of primary acquired melanosis, two compound nevi (one suspect invasive melanoma), and one dermoid-like lesion. In 18 specimens, clusters of basal epithelial cells that coexpressed cytokeratin-15/-19 and p63-α were identified at the head of the pterygium, coinciding with clinical observation of Fuchs' flecks. Our data show that significant preneoplastic lesions may be associated with pterygium and that all excised pterygia should undergo histological examination. The presence of p63-α-positive epithelial cell clusters supports the hypothesis that pterygia develop from limbal epithelial progenitors.
authors.affiliation: Inflammation and Infection Research Centre, School of Medical Sciences, University of New South Wales, Sydney, Australia.
authors.forename: Jeanie
authors.initials: J
authors.lastname: Chui
authors.forename: Minas T
authors.initials: MT
authors.lastname: Coroneo
authors.forename: Lien T
authors.initials: LT
authors.lastname: Tat
authors.forename: Roger
authors.initials: R
authors.lastname: Crouch
authors.forename: Denis
authors.initials: D
authors.lastname: Wakefield
authors.forename: Nick
authors.initials: N
authors.lastname: Di Girolamo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002449:Cell Aggregation / Q000528:radiation effects; D004848:Epithelium / Q000473:pathology / Q000528:radiation effects; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007633:Keratins / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009414:Nerve Growth Factors / Q000378:metabolism; D011230:Precancerous Conditions / Q000378:metabolism / Q000473:pathology*; D011625:Pterygium / Q000378:metabolism / Q000473:pathology*; D012008:Recurrence; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins / Q000378:metabolism; D013234:Stem Cells / Q000473:pathology* / Q000528:radiation effects; D014466:Ultraviolet Rays; D055815:Young Adult
chemical_list: D009414:Nerve Growth Factors; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins; D007633:Keratins