At present, there is no standardized treatment for renal carcinoma with eyelid metastasis. We consider that patients with renal carcinoma with eyelid metastasis should be actively treated, and patients with single eyelid metastasis without metastasis of other organs should be surgically removed. Due to the special biological characteristics of renal carcinoma cells, most renal carcinomas are not sensitive to chemotherapy and radiotherapy. Previous studys showed that the prognosis of patients with simple surgical resection and metastasis combined with postoperative radiotherapy, cytokines, and immunotherapy was not satisfactory. In the era of targeted therapy, several large retrospective studies have shown that, for patients with metastatic renal cancer who can withstand surgery, targeted therapy after tumor reduction nephrectomy has a better prognosis than simple targeted therapy[6, 7]. Besides, targeted drug combination therapy can be used as the second-line treatment for metastatic renal cancer. Following the FDA approval of sunitinib combined with everolimus for the second-line treatment based on this study in 2016, the current NCCN guidelines also recommend sunitinib combined with everolimus for the second-line treatment for patients with metastatic renal cancer[8]. The combination of targeted drugs and immune checkpoint inhibitors is also a trend in the treatment of metastatic renal cancer. Preclinical studies have shown that anti-angiogenic drugs can enhance the anti-tumor immune effect of the tumor microenvironment, and immune checkpoint inhibitors may induce a lasting response, so anti-angiogenic drugs combined with immune checkpoint inhibitors have a broad prospect for treatment strategies[9]. Therefore, for patients with single eyelid metastasis but no other metastasis, resection of primary renal carcinoma, metastasis, and combined targeted drug therapy may prolong the survival time and improve the quality of life of patients.
Distant metastases to renal clear cell carcinoma most frequently occur in the lung (45-50%), bone (10-49%), liver (14-20%), and brain (2-16%)[10]. It is unusual for RCC to metastasize to the eyelid with an eyelid mass as the first symptom. Although hematogenous spread and lymphatic metastasis are the most common routes of tumor metastasis to the eyelid, no tumor invasion of the tissues around the eye and no metastasis to the skin was observed in this patient, so it was difficult for our patient to distinguish which type of metastasis was present. It is not clear why patients with renal cancer develop metastases many years after the removal of the primary lesion. The metastasis is not necessarily related to tumor size, that is, sometimes the primary tumor is large but does not metastasize. Sometimes the tumor is small and asymptomatic but has distant metastases. The prognosis of renal cell carcinoma with multiple metastases has always been poor, and early detection of renal cell carcinoma may improve 5-year survival. Debraj Shome et al. reviewed 71 reported cases of RCC metastases to the eye from 1934 to 2004[11]. Here, we reviewed 35 cases of RCC metastases to the eyes reported in the English literature between 2004 and 2020 (Table 1)[5, 11-40]. These two studies include 107 cases with metastasis to the eyebrow (1 case, 0.93%), extraocular muscles (1 case, 0.93%), tear ducts (3 cases, 2.80%), retinal (3 cases, 2.80%), conjunctival (4 cases, 3.74%), eyelid (5 cases, 4.70%), ciliary body (6 cases, 5.61%),iris (10 cases, 9.34%), choroid (29 cases, 27.10%), orbital (39 cases, 36.44%) and the other 6 cases intraocular metastatic RCC (5.61%). Metastasis of renal cell carcinoma may occur many years after nephrectomy or maybe the first manifestation of the primary malignancy. It is associated with the latency between the initial diagnosis and metastatic presentation, which further increases the difficulty of diagnosis, so histopathological examination after the removal of the surface mass is necessary. The distant metastasis of renal cancer is often the first symptom, carefully looking for the primary foci only found in the kidney, thus it can be seen that the abnormal things in any part of the body, especially unknown sources, should think of the possibility of renal cancer metastasis.RCC metastases to the eye are rare, so urologists need to be aware of any recently discovered superficial masses during RCC follow-up.