Conjunctival Pigmented Lesions

Change Language German

Medical History

  • When was the lesion first noticed?
  • Has it changed (size, pigmentation)?
  • Personal and family history (sun exposure, skin cancer)?


  • Thorough slit lamp examination of both eyes, including lid eversion
    • Localisation, size, thickness, demarcation
    • Photo documentation
    • Anterior Segment-OCT, ultrasound (depth, scleral involvement?)

Conjunctival Naevus

  • Often present since childhood, pigmentation may change during puberty or pregnancy
  • Usually unilateral
  • Well-demarcated, often with epithelial cysts
  • Malignant transformation is rare
  • Initial photo , follow-up every 6-12 months
  • Consider excision if size, pigmentation, or vessels are suspicious

Complexion-associated Melanosis (CAM)

  • Primarily in dark-skinned individuals, may increase with age
  • Mostly bilateral, flat, diffuse, and not clearly demarcated, often near the limbus
  • Very rarely undergoes malignant transformation
  • Initial photo, follow-up every 6-12 months

Congenital ocular Melanocytosis

  • Ota naevus when involving the skin (also called Melanosis oculi or Oculodermal melanocytosis)
  • Congenital unilateral flat grayish lesion of the sclera and uvea, about 2mm from the limbus, often with periocular bluish skin pigmentation, usually no pigment in the conjunctiva
  • More common in African and Asian populations
  • Risk of uveal (not conjunctival!) melanoma is about 1:400
  • Increased risk of glaucoma
  • Follow-up every 1-2 years for melanoma and glaucoma screening

Primary Acquired Melanosis (PAM)

  • Newly acquired pigmentation in fair-skinned individuals of middle age (or older)
    • If present since childhood, it is more likely a naevus
  • Unilateral, flat, speckled golden/yellowish to brown pigmentation, poorly demarcated, non-cystic
    • Can also affect the cornea
  • Can occur with or without atypia
    • With atypia, up to 50% risk of developing melanoma!
    • Without atypia, the risk is very small
  • Differential diagnosis: naevus
    • cysts, well-demarcated, often thicker than PAM
  • Treatment
    • For small lesions (1-2 clock hours), regular monitoring (6-12 monthly) as long as stable
      • If nodules, thickening, or changed vessels, complete excision is indicated!
    • For medium-sized lesions (2-5 clock hours), complete excision + cryotherapy of the edges
    • For large lesions (>5-6 clock hours), excise thickened or suspicious areas + “map biopsy” of all quadrants
    • Consider postoperative topical Mitomycin C (0.02% or 0.04%) if the lesion cannot be completely removed

Conjunctival Melanoma

  • usually arises from PAM with atypia or de novo, transformation from naevus possible
  • Most commonly at the limbus, but also at the caruncle, tarsus, fornix
    • Non-limbal melanomas have a worse prognosis!
    • de novo has the worst prognosis
  • Elevated mass, often with feeder vessels, typically brownish, can also be amelanotic
  • Metastasis workup
  • Excision with no-touch technique
    • No incision biopsy!
    • Consider sentinel lymph node biopsy for lesions >2mm or high risk
  • Prognosis
    • Depends on the type and location
    • Local recurrences are common (up to 45% at 5 years, 59% at 10 years)
    • Mortality at 5-17% at 5 years and 9-35% at 10 years
    • ca. 1/3 with metastases after 15 years

Differential diagnoses to PAM or melanomas

  • Pingueculum, pterygium, inflammatory granuloma, amyloidosis, Axenfeld loops
  • Foreign bodies (e.g., mascara in the inferior fornix, gunpowder after explosions), Silver deposits (Argyrol eye drops), Adrenochrome pigment in the inferior fornix due to epinephrine eye drops
  • Ochronosis pigmentation at muscle insertions and in pingueculum in alkaptonuria patients
  • Hemorrhagic conjunctival cysts after surgery
  • Pigment cells in non-melanocytic tumors
  • Calcified Cogan sclera plaque at horizontal rectus muscle insertions in older patients