Jerry A. Shields
BASICS
DESCRIPTION
• Malignant tumor arising within the conjunctiva, the mucous membrane that lines the surface of the eye
• Classically pigmented but can be completely nonpigmented and appear pink
• Has prominent blood vessels feeding the tumor and within the tumor
• Tends to occur in mid to older adults and grows slowly over many months or years
• Can be unifocal or multifocal
• Painless, despite the eye appearing red and irritated
• Often manifests surrounding flat conjunctival pigment known as primary acquired melanosis that can predispose to future melanomas
• Can erode into the eye or grow deep in the orbit
• Risk for metastasis and eventual death from this cancer is approximately 25%
• Patients with this malignancy should be managed at by physicians familiar with this disease
ALERT
Any patient with a pigmented conjunctival mass should be evaluated by an ophthalmologist familiar with conjunctival tumors, particularly melanoma.
Geriatric Considerations
Most patients with conjunctival melanoma are >60 years old.
Pediatric Considerations
<1% of conjunctival melanomas occur in children.
Pregnancy Considerations
Pregnancy has not been shown to affect outcome.
EPIDEMIOLOGY
Incidence
• Race
– 5 per 10 million white population
– 1 per 10 million black population
• Sex
– 3 per 10 million female population
– 5 per 10 million male population
• Age
– 0.8 per 10 million <40 years old
– 4 per 10 million 40–59 years old
– 18 per 10 million >60 years old
Prevalence
This tumor predominantly occurs in the older Caucasian population.
RISK FACTORS
• Conjunctival nevus–<1% evolve into melanoma
• Conjunctival primary acquired melanosis (PAM) – 9–32% evolve into melanoma
– If the PAM shows severe atypia, the risk for transformation into melanoma is 13–90%.
– The greater the extent of PAM, the greater the risk for melanoma.
Genetics
• There is no single genetic abnormality commonly expressed by conjunctival melanoma.
• It is anticipated that the genetic abnormalities found with cutaneous melanoma and uveal melanoma might differ from conjunctival melanoma.
GENERAL PREVENTION
Several studies have implied that the risk for conjunctival melanoma is increasing similar to cutaneous melanoma. These studies have suggested that sun exposure could be the cause, so avoidance of excessive sun exposure could be a factor in prevention of this malignancy.
PATHOPHYSIOLOGY
The development of conjunctival melanoma is multistep, multigenetic process.
ETIOLOGY
Sunlight exposure has been postulated as a possible etiology.
COMMONLY ASSOCIATED CONDITIONS
• Lentigo maligna of the periocular cutaneous region. It is a flat pigmentation of the skin that carries 20% risk for the development of cutaneous melanoma. This condition is similar to conjunctival PAM that leads to conjunctival melanoma. Often the 2 conditions occur in the same region.
• Neurofibromatosis carries slight association.
DIAGNOSIS
HISTORY
Painless brown mass on the eye that is slow growing.
PHYSICAL EXAM
• Pigmented brown in 80%
• Nonpigmented pink in 20%
• Can occur at all sites on conjunctiva including limbus, bulbus, fornix, palpebrum, caruncle
• Size can range from<1 mm to huge, covering the entire globe at 40 mm or more
• Larger tumors have greater risks for intraocular, orbital, and lymphatic spread
• Mass has smooth reflective surface with nodular appearance and dilated feeder blood vessels
• A wreath of dilated conjunctival vessels often encircles the mass.
DIAGNOSTIC TESTS & INTERPRETATION
Lab
Initial lab tests
CBC.
Follow-up & special considerations
• Slit-lamp examination essential
• Large detailed conjunctival drawing with high magnification
• Note all areas of thickened tissue compatible with melanoma
• Note all areas of precancerous primary acquired melanosis
• Flip upper and lower eyelid to evaluate tarsal and forniceal conjunctiva
• Palpate behind orbital rim for deeper nodules
Imaging
Initial approach
• Photography of entire anterior segment of the eye, including tarsal conjunctiva
• Anterior segment optical coherence tomography if intrascleral or intraocular extension considered
• Magnetic resonance imaging if orbital extension considered
Follow-up & special considerations
Sentinel lymph node biopsy to ascertain metastasis to regional lymph nodes.
Diagnostic Procedures/Other
• Fine needle aspiration biopsy of lymph node if palpable
• No need to needle biopsy conjunctival tumor as the best treatment is complete resection.
• Do not perform incisional biopsy as this could seed the tumor.
Pathological Findings
• 4 types of atypical melanocytes within melanoma include small polyhedral spindle, balloon, round epithelioid cells with eosinophilic cytoplasm.
• Growth in sheets or nests of cells deep to the epithelium within the substantia propria
DIFFERENTIAL DIAGNOSIS
• Conjunctival nevus
• Conjunctival primary acquired melanosis
• Conjunctival racial melanosis
• Conjunctival squamous cell carcinoma
• Oculodermal melanocytosis
• Extraocular extension of uveal melanoma
• Conjunctival metastasis from cutaneous melanoma
• Ochronosis
• Conjunctival arygyrosis (silver staining)
TREATMENT
MEDICATION
Surgical excision is first line therapy. If medications are used, they only follow surgery after complete healing and might include topical mitomycin C, 5 fluorouracil, or interferon to resolve residual flat melanosis.
ADDITIONAL TREATMENT
General Measures
• Any patient with conjunctival primary acquired melanosis or nevus should be followed by a competent ophthalmologist familiar with those conditions as well as melanoma and understanding that those conditions could lead to melanoma.
• If melanosis is extensive (>2 clock hours) or evolving, then surgical resection, cryotherapy and alcohol epitheliectomy should be performed.
SURGERY/OTHER PROCEDURES
• The goal of the “no touch” surgical technique is critical for complete excision, clean margins, and avoidance of tumor shedding.
• There is no role for incisional biopsy.
• Therapeutic steps are listed below:
– Removal of corneal component with controlled absolute alcohol application followed by careful excision of corneal epithelium
– Removal of conjunctival component with complete wide surgical resection using operating microscope to achieve tumor free margins and without touching or directly manipulating the tumor (no touch technique)
– Cryotherapy to all surrounding conjunctival margins
– Excision or cryotherapy to all surrounding primary acquired melanosis
– Closure of tissue primarily or by using transpositional flap, free conjunctival graft, or amniotic membrane transplantation
– Plaque radiotherapy for intrascleral involvement
– Orbital exenteration for orbital involvement
ONGOING CARE
FOLLOW-UP RECOMMENDATIONS
• Follow closely after surgery every 3 months and if stable for 1 year without recurrence, then monitor twice yearly.
• If residual or recurrent melanoma, then surgical resection should be performed.
• If residual or recurrent melanosis, then surgical resection or cryotherapy should be performed.
Patient Monitoring
• Ophthalmic examination with photographic documentation at each visit
• Systemic evaluation for metastasis to lymph nodes, lung, and brain
PATIENT EDUCATION
PROGNOSIS
• Systemic – Metastasis occurs in 16% by 5 years, 26% by 10 years, and 32% by 15 years.
• Ocular – melanoma recurrence or new tumor occurs in 26% by 5 years, 51% by 10 years, and 65% by 15 years. Exenteration is necessary in % by 5 years, 16% by 10 years, and 32% by 15 years.
• Visual – Following treatment, vision is 20/20–20/50 in 70%, 20/60–20/100 in 6%, and 20/200 or worse (including exenteration) in approximately 24%.
COMPLICATIONS
• Vision loss
• Dry eye
• Surgical pterygium
• Symblepharon
• Ptosis
• Conjunctival scarring
• Diplopia
ADDITIONAL READING
• Shields CL, Shields JA. Tumors of the conjunctiva and cornea. Surv Ophthalmol 2004;49:3–24.
• Grossniklaus HE, Green WR, Luckenbach M, et al. Conjunctival lesions in adults: A clinical and histopathologic review. Cornea 1987;6:78–116.
• Shields CL, Demirci H, Karatza EC, et al. Clinical survey of 1643 melanocytic and nonmelanocytic conjunctival tumors. Ophthalmology 2004;111:1747–1754.
• Shields CL, Fasiudden A, Mashayekhi A, et al. Conjunctival nevi: Clinical features and natural course in 410 consecutive patients. Arch Ophthalmol 2004;122:167–175.
• Folberg R, McLean IW, Zimmerman LE. Primary acquired melanosis of the conjunctiva. Hum Pathol 1985;16:136–143.
• Shields JA, Shields CL, Mashayekhi A, et al. Primary acquired melanosis of the conjunctiva. Risks for progression to melanoma in 311 eyes. The 2006 Lorenz E. Zimmerman Lecture. Ophthalmology 2008;115(3):51–19.
• Shields CL, Shields JA, Gunduz K, et al. Conjunctival melanoma: Risk factors for recurrence, exenteration, metastasis, and death in 150 consecutive patients. Arch Ophthalmol 2000;118:1497–1507.
• Seregard S. Conjunctival melanoma. Surv Ophthalmol 1998;42:321–350.
• Yu GP, Hu DN, McCormick S, et al. Conjunctival melanoma: Is it increasing in the United States? Am J Ophthalmol 2003;135:800–6.
• Shields JA, Shields CL, De Potter P. Surgical management of conjunctival tumors. The 1994 Lynn B. McMahan Lecture. Arch Ophthalmol 1997;115:808–15.
• Shields JA, Shields CL. Conjunctival melanocytic lesions. In: Eyelid, Conjunctival, and Orbital Tumors. An atlas and textbook. Philadelphia: Lippincott Williams and Wilkins Co, 2008:307–347.
• Shields JA, Shields CL. Surgical management of conjunctival tumors. In: Eyelid, Conjunctival, and Orbital Tumors. An atlas and textbook. Philadelphia: Lippincott Williams and Wilkins Co, 2008:437–445.
CODES
ICD9
• 190.3 Malignant neoplasm of conjunctiva
• 232.1 Carcinoma in situ of eyelid, including canthus
• 372.55 Conjunctival pigmentations
CLINICAL PEARLS
• Any pigmented conjunctival mass should be examined by a qualified ophthalmologist for features of melanoma.
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