A patient presented with a large peripapillary choroidal mass as the initial manifestation of widespread, poorly differentiated, large cell lymphoma. The choroidal tumor had clinical and ultrasonographic characteristics of a uveal malignant melanoma. A systemic evaluation and fine-needle aspiration biopsy specimens of the abdomen and choroid established the diagnosis of a lymphoma. On rare occasion, other neoplasms can simulate the diagnostic pattern of uveal melanoma, and fine-needle aspiration biopsy can be crucial in establishing the correct diagnosis.