Conjunctiva: Preinvasive/Malignant Lesions

Question 1

Describe Conjunctival Intraepithelial Neoplasia & treatment?

Answer 1

• Lesion starting to show potential signs of malignancy, but epithelial basement membrane is not compromised
• Non-pigmented
• Mild/moderate/severe – depends on how much of epithelium is involved – 1,2, or 3 thirds of conj epithelium
• Carcinoma in situ when neoplasia throughout epithelium (full thickness of epithelium)
• Caused by – HPV virus or sunlight
• Associated w/ HIV in young adults
• Most commonly occur on exposed areas near limbus
• Describe:
  o Location
  o Non-pigmented or pigmented?
  o Is it elevated?
  o Size
  o Is it ulcerated?
  o Etc
• Appearance:
  o Papilliform
  o Gelatinous
  o Leukoplakic
• May be associated with inflammation & abnormal vascularisation
• Large feeder vessels – vessels which are growing into the tumour to help it to grow & proliferate at an abnormal rate
• Slow growing
• Treatment:
  o REFER URGENTLY
  o Adjunctive therapy
   Mitomycin C
   Interferon
  o Excision w/ clear margins
  o Cryotherapy to surrounding area – to make sure remove all of it
  o Risk of limbal stem cell failure

Question 2

Describe Squamous Cell Carcinoma & treatment?

Answer 2

• Invade structures underneath epithelium
• Non-pigmented
• Can be similar to the pre-invasive lesions – can be a continuation
• If any suspicion: say what see, describe lesion & refer sooner rather than later
• If any doubt – REFER
• TREATMENT:
  o Excision w/ clear borders – 4mm clear edges (large defect that would need to heal – use amniotic membrane)
  o Cryotherapy
  o Rate of recurrence dependent on clearance of margins
  o Risk of intraocular then systemic spread
  o Exenteration – removing conjunctiva, globe, muscles, everything within the orbit

Question 3

Describe Primary Acquired Melanosis (PAM)?

Answer 3

• Similar to lentigo maligna on skin
• Abnormal melanocyte proliferation of unclear aetiology
• Unilateral, flat, brown lesions
• More common in Caucasian population
• Usually benign but may progress to melanoma – suspect w/ nodularity, enlargement or increased vascularity
• Small areas may be observed – but if any changes then REFER
• Suspicion & biopsy palpebral or forniceal conj, plica or caruncle – to determine if melanoma
• Excision biopsy in large progressive lesions
• Clear margins
• Topical Mitomycin C or Interferon α

Question 4

Describe a Melanoma?

Answer 4

• Rare – 1 per 2,000,000 in Europeans
• Can metastasize but better prognosis than cutaneous melanoma
• Arise from acquired naevi/ PAM/ normal conj
• Direct spread from ciliary body (as it invades conj from within) or metastasise to conj (from elsewhere in body)
• Most common in bulbar conj or limbus
• Variable pigmentation
• Vascularised – can bleed easily – can proliferate & grow as has good blood supply – feeder vessels
• Nodular appearance
• Can be v aggressive
• Invade globe or orbit or metastasise to regional lymph nodes, brain & other sites
• Excisional biopsy w/ 4mm borders & amniotic membrane graft – to help w/ healing & reconstruction
• Cryotherapy (to ensure killing any cells around the excision) & Mitomycin C (to help shrink tumour prior to surgery & continue it after surgery too)