Anterior Segment
Ocular Surface Squamous Neoplasia
Also known as: OSSN, conjunctival intraepithelial neoplasia, CIN, squamous cell carcinoma conjunctiva, SCC conjunctiva, corneal intraepithelial neoplasia, limbal mass, conjunctival tumour
Filed as: Urgent
Source-cited from the record's own evidence list. Clinical content programme led by Dr Ankit Mathur, PhD, Grad Cert Ocu Thera, B.S. Optom. How the clinical content is governed
Clinical decision support only
Overview
A spectrum of epithelial neoplasia of the conjunctiva and cornea ranging from dysplasia (conjunctival intraepithelial neoplasia, CIN) to invasive squamous cell carcinoma. The most common ocular surface malignancy. Risk factors include UV exposure, HPV (especially type 16), immunosuppression (HIV), and old age. Presents as a raised, vascular, or leukoplakic limbal mass.
Recognition
Symptoms: what patients report
- Often asymptomatic in early disease — discovered incidentally on routine examination.
- Unilateral chronic redness, often attributed to chronic conjunctivitis.
- Mild irritation or foreign-body sensation.
- A visible 'lump' or growth on the white of the eye.
- Gradually enlarging whitish or vascular lesion at the inner or outer corner of the eye.
- Rarely: reduced vision if the lesion encroaches on the visual axis.
Signs: what the examination shows
- Raised, gelatinous, papilliform, or leukoplakic mass at the limbus — typically in the interpalpebral zone (3 or 9 o'clock).
- Intrinsic vascularity — feeder vessels or surface vessels within the lesion.
- White, opaque, or frosted surface epithelium (leukoplakia).
- Indistinct or irregular lesion borders.
- Extension onto the cornea in advanced cases.
- Salmon-pink colour (gelatinous type) or white chalky appearance (leukoplakic type).
- In immunosuppressed patients (HIV): may be large, multifocal, or rapidly growing.
What OptoGuide™ covers for ocular surface squamous neoplasia
- Pattern reasoning: what this combination of findings points to, and its differentiators
- Don't-miss risks and escalation triggers
- Management tiers with linked New Zealand therapeutics
- Referral urgency, specialty, and letter drafting
Sources
- Ocular Surface Squamous Neoplasia — EyeWiki
- Anterior Eye Disease and Therapeutics A-Z (Bruce & Loughnan) — standard reference text
- Invasive Conjunctival Melanoma Mimicking Ocular Surface Squamous Neoplasia: A Case Series. Gallo B, Thaung C, Hay G, et al. The British Journal of Ophthalmology. 2021;105(6):775-778.
- Conjunctival Lesions in Adults. A Clinical and Histopathologic Review. Grossniklaus HE, Green WR, Luckenbach M, Chan CC. Cornea. 1987;6(2):78-116.
- Conjunctival Melanoma: A Narrative Review of Current Knowledge. Papaoikonomou MA, Pavlidis L, Apalla Z, Papas A. Pigment Cell & Melanoma Research. 2025;38(2):e70006.
- Conjunctival squamous cell neoplasia: the Liverpool Ocular Oncology Centre experience — Graefes Arch Clin Exp Ophthalmol 2014 (treatment algorithm for primary and salvage groups; definitive management sits with the specialist)
- Risk factors for pterygium: Latest research progress on major pathogenesis. Ding P, Wang R, He Y. Exp Eye Res. 2024;243:109900.
- Viral involvement in the pathogenesis and clinical features of ophthalmic pterygium (Review). Chalkia AK, Spandidos DA, Detorakis ET. Int J Mol Med. 2013;32(3):539-43.
- Predictors of ocular surface squamous neoplasia recurrence after excisional surgery. Galor A, Karp CL, Oellers P, et al. Ophthalmology. 2012;119(10):1974-81.
- Primary Care Referral Guidelines – Ophthalmology (November 2025). The Royal Victorian Eye and Ear Hospital.
- Community Eyecare Guideline 3.11: Pigmented Lesions, Conjunctival. NHS Scotland. Last reviewed 5 September 2026.
- Conjunctival pigmented lesions — College of Optometrists Clinical Management Guideline
- Phenylephrine — PubChem Compound Summary for CID 6041. National Center for Biotechnology Information.
Standard texts: Kanski's Clinical Ophthalmology: A Systematic Approach, The Wills Eye Manual, Oxford Handbook of Ophthalmology, Oxford American Handbook of Ophthalmology, Signs in Ophthalmology: Causes & Differential Diagnosis.