Giant Choroidal Nevus—A Case Report

<b>Background and Clinical Significance</b>: Choroidal nevi are common benign growths originating from pigment cells in the fundus of the eye. They are typically up to 5 mm in diameter, asymptomatic, and incidentally discovered during routine ophthalmological examinations. <b>Case Presentation</b>: We present the case of a 48-year-old woman with presbyopic complaints and an incidental finding of a large, pigmented, slightly raised tumor in the fundus of the left eye. Examinations revealed normal visual acuity in both eyes and normal intraocular pressure. Ophthalmoscopy of the left eye identified a large, pigmented lesion measuring 11.55 mm in diameter, with drusen-like deposits along the superior nasal vascular arch. Fluorescein angiography showed atrophic changes in the retinal pigment epithelium without evidence of a pathological vascular network. Ultrasound revealed dimensions of 10.21 mm at the base and 0.57 mm prominence, with no changes observed during a one-year follow-up. Optical coherence tomography (OCT) did not detect any subretinal fluid. The right eye appeared normal. Based on these findings, a giant choroidal nevus in the left eye was suspected, and the clinical approach involved monitoring at 3- to 6-month intervals. <b>Discussion</b>: This case highlights the diagnostic challenges associated with a large, pigmented fundus lesion in a relatively young patient. Giant choroidal nevi, defined as lesions larger than 10 mm at the base, may clinically mimic malignant melanoma. However, features such as drusen and atrophic changes in the retinal pigment epithelium suggest a chronic process. Differentiating between giant choroidal nevi and malignant melanoma is essential due to differing therapeutic approaches. Since some choroidal nevi can undergo malignant transformation, close monitoring for signs of malignancy is crucial. <b>Conclusions</b>: The size of pigmented nevi is a significant risk factor for malignant transformation, underscoring the importance of long-term follow-up for affected patients.