1. Title “A Spot in the Dark”: A Case of Choroidal Melanoma Authors1
1Department Affiliation, University of Oklahoma School of Community Medicine
“A Spot in the Dark”: A Case of Choroidal Melanoma
Authors: Michael R Clampitt; Louis E Mulkey, DO
University of Oklahoma School of Community Medicine, Tulsa, OK
INTRODUCTION
CASE DESCRIPTION
DISCUSSION & REVIEW
Choroidal melanoma, while an uncommon diagnosis with an incidence of roughly 6.5 cases per million people in the US1, exists as the second most common type of primary malignant melanoma. It is also the most common primary tumor of the intraocular space2. Similarly to its cutaneous counterpart, choroidal melanoma is associated with an increased risk among individuals with fair completion and light iris coloring3. A unique aspect of the disease is an increased risk to those who are occupationally exposed to UV light, the largest such group being welders4. The most common site of distant metastasis is the liver and lung, both of which lead to poor outcomes.
Differential Diagnosis
Acute Exacerbation of Diabetic Retinopathy
Retinal Detachment
Retinal Hemorrhage
Choroidal Nevus/Melanoma
Initial Work Up
Patient was referred to OU Ophthalmology in July and underwent dilated fundoscopic examination, which showed a concerning lesion in the right retina. Early testing was not definitive, leaving doubt to whether this was a contained hemorrhage or a retinal malignancy. MRI was ordered at the time, however the patient was lost to follow up for several months due to insurance difficulties.
Tests
MRI in October showed a partially amelonotic mass measuring 9 mm x 9 mm x 2.7 mm, suggestive of melanoma. Confirmatory fine needle aspiration was performed in conjunction with treatment.
Final Diagnosis
The fine needle aspiration sample identified the lesion as being a High Grade (Grade II) Uveal melanoma.
Treatment
Patient was admitted to OU Presbyterian for brachytherapy of the melanoma. The lesion was treated with surgical application of a radioactive iodine-125 plaque and removal on post operative day 4 without complications. Genetic testing of the lesion estimated a 72% 5-year risk of metastasis, although this value was reported with decreased confidence due to a relatively acellular sample. She was re-evaluated in March, during which visual acuity testing indicated that her vision had stabilized, and associated scarring from her therapy was regressing appropriately. She is scheduled for follow up in July. To help prevent radiation-induced retinopathy, the patient was treated with intraocular Avastin. Recommended screening for metastasis by Ophthalmology includes: annual MRI of the liver, annual chest x-ray, and Liver Function Testing with LDH every 6 months.
Choroidal Melanoma, similar to its more common cutaneous counterpart, exists as a devastating condition with high morbidity and mortality.
Primary lesions typically expand asymptomatically until mass effect causes a central vision defect as the first presenting symptom.
Local treatment includes radiotherapy, either via brachytherapy (as performed in this case) or charged particle irradiation, with enucleation being reserved for cases of extra-scleral invasion or painful neovascular glaucoma5.
Treatment for distant metastasis in choroidal melanoma has been shown to be at best equivocal to nonocular melanoma, with the majority of patients unable to receive curative treatment.
Regular screening of patients with choroidal melanoma by the primary care provider for metastasis to the lung or liver can lead to early detection of lesions, possibly improving survival rates.
CASE PRESENTATION
Case History
The patient was a Caucasian female in her early 50s with a history of hypertension and diabetic retinopathy. She presented to a clinic visit with a chief complaint of a two week history of “flashes” in her right eye accompanied by diminished vision in the affected eye.
Physical Exam
Visual acuity was measured as 20/100 in her right eye and 20/20 in her left. Extraocular movements were intact bilaterally and pupils were equal and reactive to light. Patient’s sclerae showed no erythema or icterus. Non-dilated fundoscopic exam was indeterminate. No new abnormalities were seen on remainder of physical exam.
CONCLUSION
This case affords a view into the unique responsibility placed upon primary care providers of balancing a watchful eye for rare and threatening disorders across every specialty, while treating the common diseases which plague our patient population. The patient described throughout has complaints very often associated with her past medical history, especially carrying a long standing diagnosis of Diabetes Mellitus. Although it is a very uncommon condition, choroidal melanoma can be devastating if left undiagnosed.  It should remain a consideration in all patients with altered vision, even in those with existing chronic ophthalmic disease.
REFERENCES
Singh AD, Turell ME, Topham AK. Uveal melanoma: trends in incidence, treatment, and survival. Ophthalmology 118(9), 1881–1885 (2011).
Chang AE, Karnell LH, Menck HR. The National Cancer Data Base report on cutaneous and noncutaneous melanoma, a summary of 84,836 cases from the past decade. Cancer 83(8) (1998)
Weis E, Shah CP, Lajous M, et al. The association between host suseptablitiy factors and uveal melanoma: a meta-analysis. Arch Ophthalmol 2006; 124:54
Shah CP, Weis E, Lajous M, et al. Intermittent and chronic ultraviolet light exposure and uveal melanoma: a meta-analysis. Ophthalmology 2005; 112:1599
Collaborative Ocular Melanoma Study Group. The COMS randomized trial of iodine 125 brachytherapy for choroidal melanoma: V. Twelve-year mortality rates and prognostic factors: COMS report No. 28. Arch Ophthalmol 2006; 124:1684
Image from Radiology Assistant, John Hopkins. Credit to David Youssem
Image from: Retinal Image bank, Credit to Dr. Alex P. Hunyor MD
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