Choroidal Metastasis From Papillary Renal Cell Carcinomas: A Case Report and a Review of the Literature

Abstract

Choroidal metastasis originating from renal cell carcinomas (RCCs) is rare. To the best of our knowledge, 31 cases of choroidal metastasis from RCC have been reported in the English literature as of January 31, 2024. Nevertheless, physicians need to be vigilant in recognizing this condition, as its progression impacts the quality of life (QOL) of affected patients. In Case 1, a 60-year-old male with a medical history of papillary RCC experienced a deterioration in visual acuity (VA) and was diagnosed with solitary choroidal metastasis. Subsequently, multiple metastases were identified, prompting the initiation of a combination therapy regimen consisting of pembrolizumab plus axitinib. Despite treatment, progression of choroidal metastasis and a further decline in VA were observed. The patient underwent stereotactic radiotherapy and experienced complete resolution of the choroidal metastasis, accompanied by a slight improvement in VA. In Case 2, a 76-year-old man presented with a renal tumor accompanied by lung metastases. He underwent nephrectomy, and the histological diagnosis was papillary RCC. We initiated combination therapy consisting of nivolumab plus cabozantinib. The patient experienced a decrease in VA during treatment. We identified extensive fine metastases scattered throughout the bilateral choroid. We administered axitinib, but the patient experienced bilateral blindness. Given the absence of established therapy for choroidal metastasis, it is crucial to maintain flexibility in treatment selection. Local or systemic approaches should be used as deemed appropriate for each individual case.

Keywords: choroidal metastasis; immune checkpoint inhibitor; kidney papillary renal cell carcinoma; molecular-targeted therapy; non-clear cell renal carcinoma; renal cell carcinoma; stereotactic radiotherapy.

Figure 1. Abdominal computed tomography

a) Liver metastasis and b) metastasis to the crus of the diaphragm

Figure 2. Magnetic resonance imaging, fundoscopy, and optical coherence tomography of the choroidal metastasis

a: Magnetic resonance imaging (T2-weighted imaging) revealing an intraocular tumor in the left eye (arrow). b: Fundoscopy demonstrates pigmentary changes suggesting a neoplastic lesion (arrow). c: Optical coherence tomography at the level of the green arrow shows subretinal fluid and serous retinal detachment (*).

Figure 3. Stereotactic radiotherapy for the choroidal metastasis

a: Planning computed tomography for stereotactic radiotherapy using CyberKnife for the choroidal metastasis in the left eye. b: Magnetic resonance imaging (fat-suppressed T2-weighted image) taken 1.2 months after irradiation shows that the choroidal metastasis in the left eye had disappeared entirely.

Figure 4. Computed tomography and microscopic findings

a: Chest computed tomography reveals multiple lung metastases in the bilateral lower lobes (arrow). b: Abdominal computed tomography reveals a left renal cystic tumor measuring 10.7 cm with thickened irregular walls and solid components enhanced with contrast medium. c: Lymph node enlargement identified in the left renal hilum (arrow). d: Hematoxylin and eosin staining of the kidney tumor. Tumor cells form a papillary architecture. The scale bar in the lower right corner indicates 20 μm. e: Immunohistochemistry for cytokeratin 7 of the kidney tumor. Tumor cells are positive for cytokeratin 7. The scale bar in the lower right corner indicates 20 μm. f: Multiple lung metastases slightly decrease in size with combination therapy consisting of nivolumab and cabozantinib.

Figure 5. Magnetic resonance imaging and optical coherence tomography of choroidal metastases

a: Magnetic resonance imaging (fat-suppressed T2-weighted image) suggesting the presence of a left intraocular tumor (arrows). b: Optical coherence tomography at the level of the green arrow reveals serous retinal detachment (*) and extensive fine metastases scattered throughout the choroid (**).