Ocular Toxoplasmosis Mimicking Choroidal Metastasis From Colorectal Adenocarcinoma

The purpose of this article is to describe a case of Toxoplasma gondii chorioretinal granuloma mimicking a choroidal metastasis from colorectal adenocarcinoma. Evaluation included clinical examination with multimodal imaging techniques and chorioretinal biopsy. A 37-year-old white male with a history of colorectal adenocarcinoma presented with painless vision loss in the right eye, and fundoscopic examination revealed an amelanotic choroidal lesion. Patient history, examination, and diagnostic imaging suggested an old choroidal metastatic lesion with the patient electing chorioretinal biopsy. Upon cytologic examination, the biopsy sample indicated absence of malignant cells or tissues; however, the sample demonstrated fibroglial tissue with associated inflammation and toxoplasma organisms. This case demonstrates an atypical presentation of toxoplasma chorioretinitis that can mimic the appearance of a metastasis. Immunocompromised patients may be particularly susceptible to this atypical presentation of chorioretinitis