Choroidal Metastasis As First Presenting Sign of Renal Cell Carcinoma Without Evidence of Primary Tumour - A Case Report

Renal cell carcinoma (RCC) is a rare malignancy characterized by a variety of clinical features. It represents approximately 3 % of all adult malignancies and ranks 13th in frequency of all carcinomas.[1,2] RCC has been documented to metastasize to every organ in the body although metastasis to the eye and orbit is uncommon. Metastases may present decades after the removal of the primary disease. However, it is uncommon for patients who present with ocular metastasis before primary RCC is identified. We report a rare and unique case of metastatic renal cell carcinoma presenting as a choroidal mass despite no evidence of a primary tumour. We present a case of a 65-year-old Chinese man who had sought treatment for a right-sided painful blind eye for 2 years which progressively worsened over time. His vision was poor since the age of 15 years and he was unsure of the cause. Initially, he was treated for the painful blind eye secondary to glaucoma and went for evisceration. Intraoperatively, we noticed that his vitreous cavity was filled with hard fibrotic mass. Histopathological examination was reported as right eye metastatic renal cell carcinoma with clear cell variant. Further investigation was done and he underwent exenteration in view of right optic nerve bulkiness which was also related to renal cell carcinoma. Interestingly, no tumour marker was positive and computed tomography (CT) thorax, abdomen and pelvis did not reveal any primary tumour. He did not complain of any adverse urinary symptoms and there were no signs and symptoms to suggest a concurrent renal pathology. We report a rare and unique case of metastatic renal cell carcinoma presenting as a choroidal mass as the first presenting sign without evidence of primary tumour. Differential diagnosis of metastases must be considered in patients who present with an ocular mass, despite being asymptomatic of any primary malignancy. This is to ensure that this condition is promptly identified and treatment initiated as soon as possible. By highlighting this case, we seek to bring awareness to this condition and hopefully improve on its current dismal prognosis by early diagnosis.