Retinal Pigment Epithelium Tumorlike Lesion Arising From an Area Treated With Laser Photocoagulation

Focal hyperplasia of the retinal pigment epithelium (RPE) is a benign condition that can occur as a result of numerous ocular injuries, ^1,2 including laser photocoagulation of the choroid or retina in various disease conditions.³ It appears as an irregular, flat accumulation of black pigment under the sensory retina. It is uncommon for RPE hyperplasia to evolve into elevated, tumorlike lesions. To the best of our knowledge, there has been no documentation of such lesions from their first appearance to full development. This case report documents laser photocoagulation to treat choroidal neovascularization (CNV) associated with age-related macular degeneration evolving into RPE hyperplasia and then a tumorlike elevated lesion.

In 1991, a 62-year-old African American woman was examined for vision loss in her right eye. Her visual acuity with correction was 20/400 OD and 20/40 OS. She had a subfoveal CNV lesion with subretinal fluid, blood, and lipid components (Figure 1). A fluorescein angiogram showed subfoveal CNV, composed of classic CNV with no occult CNV, that was less than 3.5 disc areas in size.

Laser photocoagulation treatment was applied to decrease the risk of additional severe visual acuity loss.⁴ Posttreatment photographs confirmed adequate intensity throughout the area of laser treatment, which covered the lesion in its entirety. One month after treatment, the patient's visual acuity with correction was 20/800 OD.

Two months later, flat foci of RPE hyperplasia were noted. Additionally, prominent retinal folds were observed, suggesting traction by the fibrovascular tissue (Figure 2). A fluorescein angiogram showed no evidence of recurrent CNV. Hypofluorescence of the center of the lesion, caused by the RPE hyperplasia, was surrounded by a ring of hyperfluorescence associated with RPE atrophy without leakage.

During the next 4 years, areas of pigment evolved into an elevated lesion measuring 1.6 mm × 1.4 mm within a larger area of flat RPE hyperplasia and located at the center of the laser-treated area (Figure 3). Ultrasonograms (A and B scans) showed a solid highly reflective elevated lesion with a maximum height of 0.96 mm above the retinal surface. The lesion remained stable through July 2001, and the patient's visual acuity remained stable at 20/250 OD.

In 1996, laser photocoagulation was applied for extrafoveal and recurrent subfoveal CNV in the left eye. Flat hyperplastic pigmented lesions developed in this eye as well, but they did not become elevated tumorlike lesions as had occurred in the right eye.

Shields et al³ recently described a patient who underwent laser photocoagulation for central serous chorioretinopathy, in which an elevated lesion gradually enlarged, eroded through the sensory retina, and adhered to the posterior hyaloid face. No fundus photographs were available during the development of this hyperpigmented lesion. The same article described another patient with similar findings arising from what presumably began as a toxoplasmosis lesion. Both these lesions were confirmed to be benign by histopathological analysis based on material obtained by fine-needle aspiration.

In our case, the differential diagnosis of the elevated pigmented lesion is similar to what was described by Shields et al. Congenital hypertrophy of the RPE is a benign tumor that rarely can give rise to malignant adenocarcinoma. Choroidal malignant melanomas and choroidal nevi are other possible diagnoses, although small melanomas and nevi do not tend to invade the sensory retina. Unlike the cases described by Shields et al, the current report demonstrates that it is not necessary for the tumor to produce transudative retinopathy.

At our center, CNV is relatively uncommon in African Americans compared with whites, ⁵ but it is unknown if the patient's race had any relationship to the unusual hyperplasia that developed. More collective experience should provide more information regarding these lesions.

Dr Margalit is supported by the Sinai/Wilmer Fellowship Award, the Project Vision Fellowship Award, and the Wilmer Macular Research Fund. Dr Bressler is the James P. Gills Professor of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore.

Corresponding author: Neil M. Bressler, MD, Department of Ophthalmology, Johns Hopkins University School of Medicine, 550 N Broadway, Suite 115, Baltimore, MD 21205-2002 (e-mail: nmboffice@jhmi.edu).