SAN DIEGO — Every year, about 4000 patients in the United States are diagnosed with periocular melanoma, according to Geva Mannor, MD, MPH.
“Though rare, the incidence is thought to be slightly increasing, while the onset tends to occur in patients over age 40 years,” Dr. Mannor, an oculofacial plastic surgeon in the division of ophthalmology at Scripps Clinic, San Diego, said at the annual Cutaneous Malignancy Update. “It may be more common in males and welding is a risk factor. Pain and vision loss are late symptoms, and there are amelanotic variants. Gene expression profiling and other genetic testing can predict metastasis, especially expression of BRCA1-associated protein 1 (BAP1).”
. Extrapolating from the best available data, Dr. Mannor said that the annual incidence of choroidal melanoma in the United States is less than 2500, the annual incidence of eyelid melanoma is less than 750, and the annual incidence of conjunctival melanoma is less than 250 — much lower than for cutaneous melanomas. Put another way, the ratio between cutaneous and choroid melanoma is 80:1, the ratio between cutaneous and eyelid melanoma is 266:1, and the ratio between cutaneous and conjunctival melanoma is 800:1.
Dr. Mannor
Dr. Geva Mannor
According to an article published in 2021 on the topic, risk factors for periocular melanoma include light eye color (blue/gray; relative risk, 1.75), fair skin (RR, 1.80), and inability to tan (RR, 1.64), but not blonde hair. A review of 210 patients with melanoma of the eyelid from 11 studies showed that 57% were located on the lower lid, 13% were on the upper lid (“I think because the brow protects sun exposure to the upper lid,” Dr. Mannor said), 12% were on the brow, 10% were on the lateral canthus, and 2% were on the medial canthus. In addition, 35% of the eyelid melanomas were superficial spreading cases, 31% were lentigo maligna, and 19% were nodular. The mean Breslow depth was 1.36 mm and the mortality rate was 4.9%.
Dr. Mannor said that cheek and brow melanomas can extend to the inside of the eyelid and conjunctiva. “Therefore, you want to examine the inside of upper and lower eyelids,” he said at the meeting, which was hosted by the Scripps Cancer Center. “Margin-control excision of lid melanoma is the standard treatment.”
On a related note, he said that glaucoma eye drops that contain prostaglandin F2alpha induce cutaneous and iris pigmentation with varying rates depending on the specific type of prostaglandin. “There have been case reports of these eye drops causing periocular pigmentation that masquerades as suspicious, melanoma-like skin cancer, often necessitating a skin biopsy,” he said.
Dr. Mannor reported having no disclosures.