Ocular metastasis from renal malignancies – A comprehensive review

Abstract

The most common cause of intraocular mass is metastasis from other tumors. Renal malignancies, though rare, have a substantial number of cases with ocular metastasis, few of which were misdiagnosed. Many a times renal malignancies present with ocular manifestations before the primary diagnosis. Here in this article, we comprehensively reviewed 106 cases of ocular metastasis from renal malignancies published till date to the best of our knowledge. The eye is a rare site for distant metastasis because of the lack of a lymphatic system. The most common ocular structures to get involved in distant metastasis are the uveal tract, i.e., choroid, iris, and ciliary body. The most common renal tumor which metastasizes to eyes is renal cell carcinoma (RCC). RCC accounts for less than 2% of all ophthalmic metastases. Out of total 106 cases, the type of renal malignancy was known in 95 cases only, of which 92 had RCC, 1 Wilm’s tumor, 1 rhabdoid tumor, and 1 medullary carcinoma. The age ranged widely from 2 weeks old to 81 years old. The male to female ratio was 3.4:1. In total, 67.4% of cases had a previous history of RCC, while the rest 32.6% primarily presented with ophthalmic manifestations first. Treatment modalities included enucleation of the eye, debulking surgery followed by radiotherapy and/or chemotherapy and/or immunotherapy.

Ocular metastasis is known to be the most common intraocular tumor;[1] however, it is a less explored area in ophthalmology. The eye is a rare site for distant metastasis because of the lack of a lymphatic system. The secondaries in the eye occur mainly through the hematogenous route.[1,2] Therefore, ocular structures having a better blood supply are affected the most. The most common ocular structures to get involved by distant metastasis are uveal tract, i.e., choroid, iris, and ciliary body followed by other ocular structures.[3] The common primary tumors showing metastasis to the eye in descending order include breast, lung, gastrointestinal tract, etc.[4] Rarely, renal malignancies also metastasize to eye.[2,5] Sometimes, patients with primary renal tumors present with initial ophthalmic manifestations and are masqueraded as other primary ocular diseases.[6,7]

The most common renal tumor which metastasizes to eyes is renal cell carcinoma (RCC). RCC is a malignant tumor in adults and peaks in 6^th–7^th decades of life.[7] The male to female ratio (M: F) of adult RCC is about 2:1.[7,8] RCC accounts 90–95% of renal neoplasms and around 3% of all the adult malignant tumors.[8-10] The incidence of RCC has increased considerably over the last two decades, accompanied by an improved five-year survival rate. According to the WHO classification of tumors of kidney (4^th edition), there are many histological subtypes of RCC, of which clear cell RCC is the most common.[9] Most of the cases of RCC are sporadic; however, there is a known association with von Hippel Lindau (vHL) disease, a familial cancer predisposition syndrome.[11] The course of RCC is insidious.[9] RCC is usually found incidentally in radiological investigations like ultrasound, computed tomography (CT), or magnetic resonance imaging (MRI). In some patients, it may be characterized by a classical triad of clinical features, i.e. hematuria, flank pain, and abdominal swelling.[7,8] There is a lack of cautionary signs and symptoms in initial stages. The median time to metastases after the diagnosis of the primary renal tumor varies between 6 and 18 years, with duration as long as 25 years, have also been reported in the literature.[7,12] However, exceptions are always there as it is seen that some of the patients may present with ocular/distant metastases at the time of initial diagnosis of RCC,[9] and in rare cases, the patients may present with distant metastasis first even prior to the diagnosis of primary renal tumor.[11,13] Patients with distant metastasis of RCC have a poor prognosis with a median survival time of around 13 months only along with resistance to treatment options – chemotherapy and radiotherapy.[9] RCC metastasizes commonly through the venous or lymphatic system. The most common organs prone to RCC metastases in decreasing order are lungs (45%), bone (30%), liver (20%), adrenals (09%), brain (08%), etc.[9] Metastasis of RCC to the eye is rare; therefore, it has been rarely reported in literature.[9] RCC accounts for less than 2% of all ophthalmic metastases.[5] Renal metastases have been reported in various intraocular and extraocular structures which in decreasing order are choroid, iris, ciliary body,[11] recti muscle, and rarely conjunctiva and eyelid. Owing to the high blood flow, the choroid is chiefly exposed to the hematogenous spread of a tumor.[3] The common methods for diagnosis of RCC are radiological imaging studies like ultrasound, CT, and MRI. CT is the most preferred because of its high operability and sensitivity.[9] In this comprehensive article, we reviewed all the cases of ocular metastasis from renal malignancies till date.

Materials and Methods

Three databases, namely, PubMed/MEDLINE, Embase, and Scopus were systematically searched for case reports and case series published in English from the year 1939 to 2021. A total of 106 case reports have been included in this review study.

Exclusion criteria

The cases which were in other languages except for English have been excluded.

Keywords searched

Ocular metastasis, renal cell carcinoma with distant metastasis, Metastatic Renal neoplasms, Renal cell carcinoma with ocular/orbital metastasis.

Results

Gender and age-wise distribution

A total of 106 cases (1939 to 2021) have been included in this review study. The age ranged widely with a mean age of 58.8 years [Fig. 1]. The youngest patient was reported to be 2 weeks old and the oldest was 81 years old. M: F ratio was 3.4:1 with 79 males and 23 females [Fig. 2]. Sex was not available in four cases. There was a definite male predominance.

Figure 1.

Age-wise distribution of the patients

Figure 2.

Gender-wise distribution of the patients

Distribution of cases according to histological subtypes of renal tumors

Out of 106 cases, type of renal malignancy was known in 95 cases only, of which 92 had RCC, 1 Wilm’s tumor, 1 rhabdoid tumor, and 1 medullary carcinoma. Of the 92 cases with RCC, histological subtype was known in 54 cases [Fig. 3, Table 1]. All these 54 cases showed histomorphological features of clear cell RCC. Only 1 patient out of 106 cases had evidence of vHL syndrome. This unique patient showed the presence of retinal hemangioblastomas, cerebellar hemangioblastomas, and bilateral RCCs in addition to RCC metastasis to the eye after 7 years. However, it cannot be denied that retinal hemangioblastomas are still a more common ocular feature in patients with vHL syndrome rather than ocular metastasis of RCC. Another patient who was diagnosed with renal medullary carcinoma had a history of sickle cell trait. Renal medullary carcinoma affects young adults (5 to 39 years of age) and black individuals. It is commonly associated with sickle cell hemoglobinopathies.[14]

Figure 3.

Distribution of renal tumors in ocular metastasis

Table 1.

List of cases presenting with ocular metastasis from renal malignancies

Author	Year	Age	Sex	Presenting symptom	Clinical diagnosis	Type of renal tumor with histopathology diagnosis	Part of eye involved	Time period between renal malignancy and ocular metastasis
Hudson and Lister[15]	1934	55	M	yellowish white swelling on the upper third of pupillary portion of iris	NA	RCC, adenocarcinoma	Iris	2 years
Kalt and Tille[16]	1939	NA	NA	NA	NA	NA	Orbit	NA
Houghton[17]	1956	NA	NA	NA	NA	NA	Right orbit	NA
Van Arnam and Fine[18]	1957	59	M	bleeding from right side of nose and diminished visual acuity in right eye	Neoplasm of right ethmoid sinus with pansinusitis	RCC, adenocarcinoma	Right orbit	3 years
Van Arnam and Fine[18]	1957	72	M	NA	NA	RCC	Right eyebrow	NA
Amdur and Leopold[19]	1959	53	M	NA	NA	NA	Left orbit	NA
Woody and Geeraets[20]	1966	64	M	NA	NA	RCC	Right orbit	NA
David J. Apple[21]	1968	2	M	hematuria and abdominal mass	NA	Wilm’s tumor	Bilateral orbits including frontal lobes of brain	Metastasis presented earlier
Emanuel and Guerra[22]	1974	50	M	NA	NA	RCC	Right choroid	NA
Ferry and Font[23]	1974	NA	M	NA	RCC metastasis	RCC-09, clear cell	Intraocular- 07 Orbit - 02	01- NA 08 - Metastasis presented earlier
Ferry and Font[24]	1975	69	M	conjunctival redness and thickening in left eye and decreased visual acuity	RCC metastasis	RCC, clear cell	Ciliary body	Metastasis presented earlier
Laszczyk[25]	1975	56	M	diminishing visual acuity in right eye	Malignant melanoma	RCC, clear cell	Ciliary body	NA
Font and Ferry[26]	1976	NA	M	NA	NA	NA	Orbit	NA
Font and Ferry[26]	1976	NA	M	NA	NA	NA	Orbit	NA
Howard et al.[27]	1978	47	M	swelling right upper lid and diplopia	Lacrimal gland tumor	RCC	Orbit	Metastasis presented earlier
Stephens and Shields[28]	1979	NA	M	NA	NA	RCC	Choroid	NA
W. Reed Kindermann et al.[7]	1981	66	M	expanding mass in left upper eyelid	Chalazion	RCC	Eyelid	15 months
W. Reed Kindermann et al.[7]	1981	58	M	photopsia, floaters and nasal field cut in left eye	Choroidal melanoma	RCC, clear cell	Choroid	9 years
W. Reed Kindermann et al.[7]	1981	58	M	Vertical diplopia	Hemangioma	RCC, clear cell	Right orbit	15 years
Wyzinski et al.[29]	1981	60	M	decrease in visual acuity in right eye	Metastasis	RCC, clear cell	Bilateral Iris	Metastasis presented earlier
Denby et al.[30]	1986	65	M	diplopia	Dacroadenitis/lacrimal gland tumor	RCC, clear cell	Right Lacrimal gland	Metastasis presented earlier
Holbach et al.[31]	1990	75	M	decreased visual acuity of right eye	Metastasis	RCC, clear cell	Right Choroid	16 years
Portnoy et al.[32]	1991	65	M	decreased vision in left eye	Iris cyst/adenoma/metastasis/leiomyoma	RCC, clear cell	Left Iris	Metastasis presented earlier
M. Akhtar et al.[33]	1991	2 weeks	M	proptosis of left eye	Retinoblastoma	Mesenchymal tumor, Rhabdoid tumor	Orbit	Metastasis presented earlier
Tijl et al.[34]	1992	60	F	diplopia	Metastasis	RCC	Right orbit	5 months
Tijl et al.[34]	1992	72	F	proptosis	Metastasis	RCC	Left orbit	Metastasis presented earlier
Parnes et al.[35]	1993	53	M	proptosis and visual disturbances	Metastasis	RCC	Right orbit	Metastasis presented earlier
Woline[36]	1993	66	M	NA	NA	RCC	Right orbit	Metastasis presented earlier
Bersani et al.[37]	1994	50	M	decreased vision and dull orbital pain in left eye	Metastasis	RCC, clear cell	Left orbit	15 years
Holt et al.[38]	1994	56	M	NA	Metastasis	RCC	Left orbit	Metastasis presented earlier
Holt et al.[38]	1994	60	M	NA	Metastasis	RCC	Left orbit	Metastasis presented earlier
Langmann and Müllner[39]	1994	56	M	blurred vision in left eye	Metastasis	RCC	Left Choroid	6 months
Günalp and Gündüz[40]	1995	NA	NA	NA	NA	NA	Orbit	NA
Shields et al.[41]	1995	NA	NA	NA	NA	NA	Iris	NA
Haimovici et al.[42]	1997	54	M	dryness and foreign body sensation in left eye	Metastasis	RCC	Left Choroid	Metastasis presented earlier
Haimovici et al.[42]	1997	62	M	decreased vision, floaters and pain in left eye	Metastasis	RCC	Bilateral Choroid	Metastasis presented earlier
Haimovici et al.[42]	1997	48	M	metamorphopsia and blurring in right eye	Metastasis	RCC	Right Choroid	Metastasis presented earlier
Haimovici et al.[42]	1997	66	F	photopsis and blurred vision in left eye	Metastasis	RCC, clear cell	Left Choroid	9 years
Haimovici et al.[42]	1997	77	M	decreased vision in right eye	Metastasis	RCC	Right Choroid	6 years
Mezer et al.[2]	1997	70	F	Visual disturbances in right eye	Amaurosis fugax	RCC	Right Orbit	7 years
Shields et al.[43]	1997	Mean -65	M: F 8:1	NA	Metastasis	RCC in 09 cases	Iris – 1 Ciliary body – 1 Choroid - 8	NA
Slamovits and Burde[44]	1998	63	M	NA	NA	NA	Bilateral extraocular muscles	NA
Ware et al.[45]	1999	70	M	decreased visual acuity and tenderness in left eye	Neoplasm	RCC, clear cell	Left Iris (Left bulbar conjunctiva)	Metastasis presented earlier
Ikeda et al.[46]	2000	55	M	decreased vision in right eye	Metastasis	RCC, clear cell	Right Iris and Ciliary Body	2 years
Shields et al.[47]	2001	40-59	M	decreased vision, pain, diplopia	Metastasis	RCC	Orbit	NA
Shields et al.[47]	2001	40-59	M	decreased vision, pain, diplopia	Metastasis	RCC	Orbit	NA
Shields et al.[47]	2001	60-79	M	decreased vision, pain, diplopia	Metastasis	RCC	Orbit	NA
Shields et al.[47]	2001	60-79	M	decreased vision, pain, diplopia	Metastasis	RCC	Orbit	NA
Shields et al.[47]	2001	60-79	M	decreased vision, pain, diplopia	Metastasis	RCC	Orbit	NA
Shields et al.[48]	2001	59	M	NA	Metastasis	RCC	Palpebral lobe of Lacrimal Gland and Right Choroid	4 years
Sathish Srinivasan and Gray[49]	2003	38	M	defective central vision in right eye	Choroidal metastasis	RCC, clear cell	Choroid	2 months
Hammad et al.[50]	2003	48	F	NA	NA	RCC	Left Choroid	Metastasis presented earlier
Zdinak et al.[14]	2004	39	M	painful left eye proptosis	Sinusitis	Renal medullary carcinoma (history of sickle cell trait)	Left Orbit	Metastasis presented earlier
Richard H. Hart et al.[6]	2005	70	M	Diplopia	NA	RCC, clear cell	Lateral rectus muscle	2 years
Antonio Carlos Lima Pompeu et al.[51]	2005	59	M	Diplopia in right eye	Metastasis	RCC, Tubulo- papillary Clear cell	Inferior Rectus muscle	Metastasis presented earlier
Antonio Carlos Lima Pompeu et al.[51]	2005	72	M	Ulcerated lesion on inferior tarsal conjunctiva on right eye	NA	RCC, clear cell	Tarsal conjunctiva	Metastasis presented earlier
Debraj Shome et al.[11]	2007	67	M	Painless reduction in vision in left eye	NA	RCC, clear cell	Ciliary body	1 year
Debraj Shome et al.[11]	2007	58	M	proptosis and decrease in vision in left eye	NA	RCC, clear cell	Left orbit	14 months
Debraj Shome et al.[11]	2007	23	F	proptosis and decrease in vision in right eye	RCC metastasis	RCC, clear cell	Right orbit	Metastasis presented earlier
Passorn Preechawai et al.[4]	2007	48	M	painless protrusion of left eye	Orbital cysticercosis	RCC	Superior rectus	Metastasis presented earlier
Vito Mancini et al.[8]	2008	42	M	inflammatory symptoms	Metastasis	RCC, clear cell	Ciliary muscle	6 years
Tarek Alasil et al.[52]	2011	65	M	Blurry vision and pain in right eye, nausea, right sided headache	Acute angle closure glaucoma	RCC, clear cell	Ciliary body	15 years
Ruju Rai, et al.[5]	2014	73	F	painful proptosis, ptosis and redness of the OD	Ocular hemangioblastoma/metastatic orbital RCC	RCC, clear cell (vHL patient)	Eyeball and orbit	7 years
Claudine Bellerive et al.[12]	2016	73	M	blurred vision in right eye	Choroidal melanoma	RCC, clear cell	Choroid	25 years
Ismail Essadi et al.[3]	2017	62	M	monophthalmitis	NA	RCC, clear cell	Choroid	2.5 years
Bernadete Ayres et al.[53]	2017	81	M	blurred vision in left eye	NA	RCC, clear cell	Choroid	9 years
Margaret Wong et al.[10]	2017	70	M	decreased vision in left eye	RCC metastasis	RCC, clear cell	Ciliary body	2 years
Komanski et al.[54]	2017	73	M	Redness and blurred vision of left eye	RCC metastasis	RCC, clear cell	Ciliary body and choroid	4 years
An-Ning Chao et al.[55]	2020	50	M	Rapidly growing caruncle lesion in right eye	NA	RCC, clear cell	Choroid	1 year
Qi Bin Xu et al.[56]	2021	45	F	painless occlusion of the vision field of left eye	RCC metastasis	RCC	Choroid	1 year
Yong S. Lee et al.[13]	2021	70	M	blurry vision, diplopia and left upper eyelid mass	RCC metastasis	RCC, clear cell	Eyelid	5 years
Tie Sun et al.[9]	2021	<50-03 >50-15	M- 5 F- 13	NA	NA	RCC in 15, clear cell Others - 03 cases	NA	NA
Shu Yu Tan et al.[57]	2021	73	F	blurring of vision, diplopia, and proptosis of left eye	Metastasis	RCC	Left orbit	Metastasis presented earlier

Cases with known primary renal tumor versus an occult primary

Of the 95 cases with renal tumor and ocular metastasis, 64 cases (67.4%) had a previous history of RCC, while the rest of the 31 patients (32.6%) primarily presented with vague and nonspecific ocular symptoms before the diagnosis of primary renal tumor, i.e. the patients presented with ophthalmic metastasis with an occult primary. The common ocular symptoms include decreased vision, diplopia, pain, proptosis, nausea, unilateral headache, or a mass on an eyelid [Fig. 4].

Figure 4.

Status of primary renal tumors/ocular metastasis at the time of diagnosis

Time to metastasis

Thirty patients out of 64 cases with a previous history of RCC, presented with ocular metastasis after a period ranging from 2 months to as long as 25 years, while, in rest of the 34 patients, time duration was not discussed in the literature [Table 1].

Involvement of distant sites from renal malignancy metastasis

Renal malignancy metastasis to the eye was largely unilateral with only five cases exhibiting bilateral metastasis. The data on specific site involvement in the orbit/eye was available in 88 cases out of a total of 106 cases. The most common site involved was intraocular (n = 47/88; 53.4%) followed by orbit (n = 36/88; 40.9%), both intraocular and intraorbital (n = 2/88; 2.3%), eyelid (n = 2/88; 2.3%), and eyebrow (n = 1/88; 1.1%). Few cases also showed multiple site involvement in the same eye. Among intraocular structures, the most common part affected was the choroid (25/46; 54.3%). Other intraocular sites included were the iris and ciliary body. Among intraorbital involvement, common sites affected were recti muscles, lacrimal glands, and conjunctiva [Table 2]. Another important finding observed was that 19 patients showed metastasis from the primary RCC exclusively to the eye/orbit only without evidence of any other distant metastatic site involvement. However, in other patients, there was synchronous or metachronous metastasis to other sites as well in addition to ocular metastasis (the data of other distant site metastasis in addition to ocular metastasis was available only for 56 patients). Common sites included lung, bone (vertebrae, skull vault), lymph nodes (retroperitoneal, peripancreatic, mediastinal, hilar, abdominal), paranasal sinuses, brain, liver, pancreas, cerebellum, and adrenal glands [Fig. 5].

Table 2.

Site of eye involvement by metastatic renal tumors

Part of eye involved	Number of cases (n=88)	Laterality
Intraocular	47	Unilateral - 44 cases
Choroid	25	Bilateral - 03 cases
Iris	06
Ciliary body	07
Not specified	07
Both iris and ciliary body	01
Conjunctiva	01
Intraorbital	36	Unilateral - 34 cases
Recti muscles	04	Bilateral - 02 cases
Lacrimal gland	01
Not specified	31
Both intraocular and intraorbital	02
Eyelid	02
Eyebrow	01

Figure 5.

Distant metastasis of renal malignancies in addition to ocular metastasis

Symptoms of ophthalmic involvement by renal malignancy metastasis

Depending upon the site involved (intraocular or intraorbital), patients presented with a wide range of nonspecific clinical symptoms range from mass effects to inflammatory symptoms. Symptoms include decreased visual acuity, blurred vision, diplopia, photopsia, metamorphopsia to proptosis, conjunctival redness, eyelid swelling, and pain. It was observed that both groups of patients, i.e., patients with an already known primary renal tumor or who presented with an initial ophthalmic manifestation experienced similar eye symptoms as described above.

Diagnostic modalities and management

Only a few of the authors have described the orbital or ocular mass in detail. The most common radiological modalities used for the diagnosis were ultrasound, MRI, CT of the brain and orbit, and retinal angiography. It showed a yellow dome-shaped mass to pink fleshy or purple color mass ranging in size from 2.8 × 1.5 mm to 15 × 15 × 10 mm. Depending on the size and sites of metastasis, and the patient’s consent, treatment modalities included enucleation of the eye, de-bulking surgery followed by radiotherapy and/or chemotherapy and/or immunotherapy. However, no comments were made by the authors on subretinal fluid.

Clinical diagnosis of metastatic tumor

Of the total 106 cases, clinical diagnosis was available only for 66 cases, out of which the ophthalmologist made an outright clinical diagnosis of metastasis in 51 cases (77.3%). In the rest of the 15 cases, the diagnosis ranged from nonneoplastic conditions like glaucoma, amaurosis fugax, chalazion, and cysticercosis to neoplastic conditions like hemangioblastoma, retinoblastoma, lacrimal gland tumor, and malignant melanoma of eye [Table 1].

Systemic outcomes

Of the 106 cases, results of mortality were not available in 70 cases. Of the remaining 36 patients, the cases who succumbed to death were 20 (55.5%).

Discussion

RCC is the most common renal malignancy comprising approximately 85% of renal tumors.[9] It is a highly malignant tumor with an increased rate of systemic metastasis. With the advancement in research study, surgery, adjuvant treatment with radiotherapy, chemotherapy, and immunotherapy, the survival rate of patients with RCC has been improved markedly. However, the prognosis of patients with distant metastasis of RCC is abysmal.

Males are affected more commonly than females and the greatest incidence of primary tumors occurs in the sixth decade as described by Kinderman et al.[7,8]

Eye is an uncommon site for metastasis. Most common tumors to metastasize to orbit are breast, prostate, gastrointestinal tract, and lung.[2] Renal tumors are an infrequent cause of orbital metastasis as described by Kinderman et al. in 1981.[7] Ferry and Font in their study of 227 cases metastatic to eye and orbit found that 8.3% of ocular metastatic cases were caused by RCC.[23] Ferry and Font in their study also described three main categories of localization of ocular metastasis by RCCC – intraocular being the most common followed by intraorbital and both intraocular and intraorbital.[24] In our review study also, a predominantly intraocular site was involved followed by intraorbital structures. Ruju et al.[5] also described similar findings as above in his study. Of the intraocular sites, the choroid was the predominant site of involvement. Iris and ciliary bodies were less commonly involved. Similar findings have also been described by Shields et al.[47] and Stephen and Shields[28] in their study. Metastasis to choroid from renal tumors should be clinically distinguished by the ophthalmologist from the other choroidal lesions like hemangioma, amelanotic melanoma, or metastasis from other primary tumors.[11] Shields et al.,[43] in their review of 520 cases with uveal metastases, found that metastatic deposits from RCC tended to be thicker than other uveal metastases. They observed that the mean thickness was approximately 4 mm, and it was almost double the thickness of metastatic deposits from breast cancer.

Most cases of RCC with distant metastasis have a known primary neoplasm (n = 64 in our study). However, in some cases, patients may present with orbital symptoms preceding the diagnosis of primary renal tumor (n = 31 in our study). This fact has also been observed and explained by Parnes et al.[35] and Zdinak et al.[14] in their respective studies. RCC can recur as metastasis at any time after the initial treatment of the primary tumor. In our review study, the time period between the primary RCC and ocular metastasis ranged widely from 2 months to 25 years. The varied interval between the renal primary and its metastasis has also been well described by Haimovici et al.[42] and Bellerive et al.[12] in their studies. As already described above, RCC metastasis to distant sites is more common with clear cell variants. Also, 19 patients (17.9%) had only ocular metastasis.[2,6,7,11,13,24,16,25,27,30-32,42,45,51,54,56] There was no other distant metastasis seen in such cases. Therefore, screening of eyes with regular follow-up should be advised for all the patients diagnosed with RCC, especially clear cell variant for the early diagnosis of metastasis. Our study also revealed that commonly the ocular metastasis of renal malignancies presented as unilateral mass with just few bilateral cases. Hence, clinicians should also be aware that if a patient presents with an ocular mass, unilateral or bilateral, metastasis should always be kept as its differential diagnosis.[2] According to VM Cohen, the most helpful radiological investigation is an ocular ultrasound. B scan ocular ultrasound combined with Doppler blood flow velocity should be performed on every patient with an intraocular mass lesion.[1] Metastases are typically placoid shaped with an undulating surface and show medium to high blood flow velocity.[1] Earlier, metastatic RCC was considered to have a poor prognosis with limited treatment options like cytokine therapy. However, recently, there has been the introduction of new drugs like everolimus, bevacizumab for the treatment of metastatic RCC which has now improved the prognosis of these patients.[3,10]

Metastatic renal cell tumors have a high mortality rate. The five-year survival rate of metastatic RCC is less than 10% and a median survival time is around 13 months.[9] However, according to Zdinak et al.,[14] the mortality rate associated with renal medullary carcinoma is close to 100%. The mortality rate of ocular metastasis of renal malignancies has not been documented in literature. Our review of cases revealed a mortality rate of 55.5% in such patients [Table 3].

Table 3.

Summarized data of ocular metastasis from renal malignancies

Total number of cases	Age	Sex	History of renal tumor	Time duration between rrenal malignancies and metastasis	Laterality of ocular involvement	Part of eye involved
n=106	2 weeks-81 years (Mean age–58.8 years)	Males - 78 Females - 23 (M: F–3.4:1) Unknown gender- 05	95 cases (64 cases- previous history present) (31 cases- metastasis earlier than primary tumor) Unknown cases- 11	2 months-25 years	Unilateral - 83 Bilateral - 05 Unknown - 18	Intraocular (n=47) Intraorbital (n=36) Both (n=02) Eyelid (n=02) Eyebrow (n=01) Unknown (n=18)

Conclusion

Ocular metastasis from renal malignancies is rare but not an uncommon phenomenon. It is less described in literature as it is less commonly diagnosed. It can masquerade as a benign or malignant lesion, therefore, can be clinically confusing. Ophthalmologists and pathologists must be aware of this possibility while diagnosing ocular masses and should not misdiagnose it even if presentation is unilateral. Patients with clear cell type of RCC can undergo ophthalmic screening since its metastasis is most common and has dismal outcome. Early detection and avoidance of misdiagnosis can help in increasing the survival rate of the patient.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.