West Coast Retina
Case of the Month
A 64-year-old male with 3 weeks of blurred vision in his left eye.
Figure 1: Fundus photograph montage of the left eye. Note the amelanotic lesion extending from the temporal macula. Some pigment clumping is present over its surface.
A 64-year-old male presented with 3 weeks of blurred vision in his left eye. His past ocular history was unremarkable. His past medical history was noteworthy for the diagnosis of metastatic nonsmall cell lung carcinoma (NSCLC) 2 months earlier. Systemic evaluation revealed metastatic lesions in his brain. He had recently completed cyberknife treatment for these brain lesions. His lung cancer was anaplastic lymphoma kinase (ALK) positive, and had been started on Crizotonib 3 days earlier.
His vision in the right eye was 20/20 and 20/32 in the left eye. Examination of the right eye was unremarkable. Examination of the left eye showed no abnormalities in the anterior segment. Dilated examination of the retina revealed an amelanotic mass extending temporally from the edge of the fovea (Fig 1). It measured 6 mm x 7.5 mm with some mild pigment clumping over its surface. A small sensory retinal detachment was present in the fovea. No other lesions were present in this eye.
Spectral domain OCT studies, including enhanced depth imaging of the left eye confirmed a small amount subfoveal fluid, and a choroidal lesion temporally (Fig 2A). Some subretinal fluid was present over the surface of the mass Significant degenerative changes were present within the retinal pigment epithelial layer with multiple areas of clumps, and a somewhat corrugated appearance creating a ‘lumpy-bumpy’ contour (Fig 2B). B-scan ultrasonography confirmed the mass lesion.
Figures 2A and B: Enhanced depth optical coherence tomography imaging of the macula (Fig 2A) and the surface of the lesion (Figure 2B). Note the subretinal fluid in the macula and the elevated lesion extending temporally from the edge of the fovea. The surface of the tumor shows a 'lumpy-bumpy'.
What is your Diagnosis?
The differential diagnosis for amelanotic choroidal lesions includes: nevus, melanoma, metastasis, hemangioma, osteoma, granuloma as well as other more rare considerations.
Given the findings of an amelanotic mass in a patient with known metastatic disease, metastasis is the most likely consideration. Consistent with this, is the presence of a mass lesion with RPE clumping over its surface producing an early ‘leopard-spot’ appearance.1,2 Ultrasound evaluation showed a mass lesion with a medium-high irregular reflectivity (not shown) that is also consistent with a metastatic lesion. Recently, enhanced depth imaging OCT (OCT-EDI) has provided additional diagnostic information for choroidal lesions.3 Due to its higher resolution, it is possible to image smaller lesions and obtain thickness measurements. Additionally, other characteristics of choroidal lesions and secondary changes can be imaged that has not been previously possible. In our case, the irregular surface of the RPE/Bruch’s membrane complex as well as the multiple ‘clumps’ noted is most consistent with a metastatic lesion. It should be noted however, that this appearance is not pathognomonic.
In this case, all of the findings were consistent with a metastatic lesion.2 This patient had known systemic disease. However, in patients presenting with a choroidal metastatic lesion, it is not uncommon for a patient with a choroidal metastasis due to lung cancer to have no known history of cancer. This is in contrast to breast cancer in which a choroidal metastasis occurs more commonly in someone with a prior history of treatment for breast cancer.
The challenge in this case, is management. When a choroidal metastasis is present, treatment options include local radiation treatment (plaque brachytherapy, proton beam, or external radiation), or systemic chemotherapy. While radiation is extremely effective, it is usually a second line treatment. When external beam radiation is done, treatment to surrounding structures may limit treatment options in the future. While plaque radiotherapy and proton beam treatment limit this, both require a surgical procedure, and are therefore more involved. Other options that have been tried include intravitreal avastin, which has had limited success. As the choroid is highly vascular, and does not present a barrier to access to systemic chemotherapy, the use of systemic drugs are preferable.
Our patient’s tumor was positive for anaplastic lymphoma kinase. Rearrangements in this gene occur in approximately 3-5% of patients with NSCLC. This cancer typically occurs in younger people without a history of smoking, or a light smoking history. The presence of this gene mutation made targeted therapy possible. A newly released drug, Crizotinib, had been started 3 days prior to his initial visit with us.4
Figures 3A and B: Color fundus photograph montage the left eye 3 weeks (Figure 3A) and 6 weeks (Figure 3B) after treatment with Crizotinib. The elevation of the tumor has decreased significantly which is better seen on the enhanced depth OCT studies below.
Figures 4A and B: Enhanced depth optical coherence tomography scans of the left eye 3 weeks (Figure 4A) and 6 weeks (Figure 4B) after treatment with Crizotinib. Note the marked flattening of the tumor over time, particularly in comparison to pre-treatment (Figure 2A).
Our patient returned 3 weeks (Figure 3A) and 6 weeks (Figure 3B) following his initial visit. Evaluation at that time showed improved vision (20/25 and 20/20, respectively), with marked flattening of the metastatic lesion and resolution of the subretinal fluid (Figures 4A and B). He will be continued to be followed on this current regimen.
Take Home Points
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