--- title: "High-Risk Features in Conjunctival Pigmented Lesions: PAM, Forniceal Location and Feeder Vessels" description: "Most conjunctival pigmented lesions are benign, but some patterns require a higher index of suspicion. Red flags include: - Adult-onset, flat, patchy pigment suggestive of primary acquired melanosis (PAM) rather than a long-standing naevus ¹ - Hidden locations: fornix, tarsal…" url: "https://bluefinvision.com/knowledge-base/topics/symptoms-signs/high-risk-features-in-conjunctival-pigmented-lesions-pam-forniceal-location-and-feeder-vessels/" updated: "2026-02-16" category: "Symptoms & Signs" --- # High-Risk Features in Conjunctival Pigmented Lesions: PAM, Forniceal Location and Feeder Vessels Most conjunctival pigmented lesions are benign, but some patterns require a higher index of suspicion. Red flags include: - Adult-onset, flat, patchy pigment suggestive of primary acquired melanosis (PAM) rather than a long-standing naevus ¹ - Hidden locations: fornix, tarsal conjunctiva, caruncle (less typical for benign conjunctival naevi) - New feeder vessels, nodularity, thickening, ulceration, or inflammation - Documented change in size or colour over serial photos Population-based data show that conjunctival tumours are more often benign than malignant overall, but malignant lesions do occur, so the aim is to identify the minority that warrant specialist-led management. ² PAM is particularly important because atypia and extent are linked to melanoma risk, and clinical appearance alone may not reliably predict histology. ¹ ³ For this reason, suspicious conjunctival pigment should be managed with baseline high-resolution photography, clear mapping of involved areas, and referral to ocular oncology when features suggest PAM with atypia or melanoma-suspect change. **References** 1. Shields JA, Shields CL, Mashayekhi A, Marr BP, Benavides R, Thangappan A, et al. Primary acquired melanosis of the conjunctiva: experience with 311 eyes. Ophthalmology. 2008;115(3):511-519.e2. doi:10.1016/j.ophtha.2007.07.003. PMID: 17884168. 2. Dalvin LA, Salomão DR, Patel SV. Population-based incidence of conjunctival tumors in Olmsted County, Minnesota. British Journal of Ophthalmology. 2018;102(12):1728-1734. doi:10.1136/bjophthalmol-2017-311530. PMID: 29511061. 3. Wong JR, Nanji AA, Galor A, Karp CL. Management of conjunctival melanoma and primary acquired melanosis. Clinical Ophthalmology. 2014;8:197-206. doi:10.2147/OPTH.S45987. PMID: 25580155. **Related Topics** - [When Does a "Freckle" in the Eye Become Concerning?](https://bluefinvision.com/blog/when-does-a-freckle-in-the-eye-become-concerning/) - [What Does a "Freckle in the Eye" Actually Mean? 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