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Ocular System ORGAN SYSTEMS

Ocular melanoma

Melanoma (malignant tumors derived from melanocytes) in the eye.

Melanoma (malignant tumors derived from melanocytes) in the eye.

  • #2 M/C type of melanoma after cutaneous
  • M/C primary intraocular malignant tumor in adults

Classification

Uveal melanoma (M/C site of origin of ocular melanomas, 82.5% cases)

M/C primary intraocular malignant tumor in adults
  • Choroidal melanoma (85%–90%)
  • Iris melanoma (3%–5%)
  • Ciliary body melanoma (5%–8%)

Conjunctival melanoma (less common)

Conjunctival melanomas arise from melanocytes located in the basal layer of the epithelium of the conjunctival membrane

Aetiology

Primary tumours

M/C type of ocular melanoma (95% cases)

Secondaries (metastasis) from other foci:

  • Breast cancer (M/C)

Risk factors:

  • Uveal melanoma:
    • Congenital ocular and oculodermal melanocytosis (nevus of Ota)
    • Uveal nevus
    • UV exposure
  • Conjunctival melanoma:
    • Primary acquired melanosis (PAM) (60% of conjunctival melanomas arise from PAM)
    • Conjunctival nevus
    • UV exposure

Clinical features

Uveal melanoma:

Presentation of uveal melanoma mainly depends on size and location of the tumor and can vary from asymptomatic, detected incidentally on eye examination, over various visual disturbances to visual loss in the affected eye.
  • Blurred vision
  • Visual field defect
  • Photopsia
  • Irritation and pain, but symptoms as metamorphopsia, floaters, redness and pressure can
Slit-lamp appearances of anterior uveal melanomas, showing: (a) a ciliary body melanoma extending into anterior chamber; (b) a pigmented, nodular iris melanoma; (c) an amelanotic, nodular iris melanoma∗; and (d) a diffuse iris melanoma with seeding. | Ocular Tumours, B Damato. Butterworth Heinemann (2000).

Conjunctival melanoma:

Conjunctival melanoma usually presents as raised pigmented lesion often surrounded with prominent feeder blood vessels or areas of PAM.
  • Pigmented spot/lump
  • Irritation & pain (rare)
Slit-lamp photographs showing: (a) conjunctival melanocytic intraepithelial neoplasia; (b) diffuse, invasive conjunctival melanoma; (c) bulbar invasive conjunctival melanoma; and (d) caruncular invasive conjunctival melanoma. | Damato B and Coupland SE. Management of conjunctival melanoma. Expert Rev. Anticancer Ther. 2009;9:1227–39.

Complications

Choroidal melanoma:

  • Secondary retinal detachment with consequent visual loss
  • Rupture Bruch’s membrane acquiring mushroom shape

Ciliary body melanoma:

  • Lens displacement
  • Localized cataract
  • Increased IOP

Iris melanoma:

  • Distortion of pupil
  • Localized cataract
  • Hyphema
  • Secondary glaucoma (due to obstruction of aqueous outflow from the eye)

Diagnosis

Diagnosis is in most cases established by clinical examination with great accuracy.

Fluorescein angiography:

  • Double circulation

B-scan ultrasound:

  • Collarstud appearance (mushroom shape)

Management

Uveal melanoma:

Management of uveal melanoma varies from observation to orbital exenteration depending on the particular case, and mostly depending on the site, size of tumor and local extension.
  • Plaque radiation therapy 
  • Particle beam radiotherapy
  • Transpupillary thermotherapy
  • Laser photocoagulation
  • Gamma knife stereotactic radiosurgery
  • Local surgical resection
  • Enucleation

Conjunctival melanoma:

Wide local excision with adjuvant therapy, including brachytherapy, cryotherapy and topical application of chemotherapeutic agent (Mytomicin C).

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