Case Report: Choroidal metastasis from lung cancer

Introduction

Pulmonary squamous cell carcinoma (SCC) is a common form of lung cancer, primarily affecting smokers. However, the presence of ocular metastases remains a rare and unusual presentation. Metastasis to the eye is commonly seen with melanoma or breast cancer, but it can occasionally be found in other solid tumors. This case report aims to describe a patient with plurimetastatic pulmonary SCC with a unique presentation of ocular metastasis.

Case report

A 61-year-old male, a 40-pack-year smoker currently not in cessation and working as a civil servant, presented to our hospital with progressive exertional dyspnea, dry cough, and a four-month history of general health deterioration. He had a history of surgically treated renal stones but no significant family history, particularly no history of cancer. Additionally, he reported gradual visual impairment in the right eye. On clinical examination, the patient was in good general condition with a performance status of 0. The examination revealed an intact neurological status, with no sensory-motor deficits, stable hemodynamic and respiratory parameters, and no abnormal lymph node palpation.

Imaging findings

A chest CT scan revealed a left hilar mass with associated lower lobar carcinomatous consolidation, trans-scisural lingular extension, bilateral parenchymal nodules, and left pleural effusion with pleural nodules. Further staging work-up included an abdominal-pelvic CT, which showed enlarged left gastric and retroperitoneal lymph nodes. A brain CT showed no secondary lesions in the brain.

Ophthalmological examination revealed a reduction in visual acuity to light perception in the right eye, while the left eye was unaffected. Fundus examination revealed two choroidal lesions in the right eye. Orbital MRI demonstrated a subretinal intraocular lesion, measuring 11×5 mm, located in the posterior-medial and superior region of the right eye, with intermediate signal intensity on T1-weighted imaging and hypointensity on T2-weighted imaging (Please see Figure 1, Figure 2 and Figure 3).

Figure 1. T1-weighted MRI axial orbital section showing a subretinal intraocular lesion in the right eye.

Figure 2. T1-weighted MRI axial orbital section demonstrating the lesion's posterior-medial and superior location.

Figure 3. T1-weighted MRI sagittal orbital section highlighting the lesion's dimensions.

Discussion

Ocular metastases are rare in lung cancer, found in 0.7 to 12% of lung cancer patients.^1,2 The choroid is the most commonly affected ocular site, with choroidal metastases representing 88% of all ocular metastases in the study by Shields et al.³ The hematogenous spread of the primary cancer, particularly via the posterior ciliary arteries, explains the preferential location of these metastases in the postero-supero-lateral choroid, a highly vascularized region.^1,4

Choroidal metastases are primarily seen in breast and lung cancers, with lung cancer being the leading cause of choroidal metastases in the male population.⁵ They are rarely isolated and typically form part of a broader metastatic disease. In our case, pulmonary and pleural metastases were also identified.^6,7

Choroidal metastases are often asymptomatic, and orbital metastasis is rarely the first sign of lung cancer.^8,9 The most common clinical sign is exophthalmos, which can develop rapidly but often remains subtle in 66% of cases.¹⁰ Frequent early indicators include diplopia, metamorphopsia, and visual acuity decline.^1,11 In our case, the patient reported progressive visual acuity loss in the right eye.

Diagnosing the etiology of a choroidal mass can be challenging, with differential diagnoses including metastasis, melanoma, or choroidal hemangioma.¹² The definitive diagnosis is based on biopsy, guided by imaging, with immunohistochemical analysis.¹³ In our case, the orbital biopsy was not performed, and the diagnosis was made based on the characteristic CT findings suggestive of a secondary origin, confirmed by histological confirmation of the pulmonary primary via bronchial biopsies.

Management requires a multidisciplinary approach involving ophthalmologists, pulmonologists, and oncologists. The reference treatment is radiotherapy, with doses ranging from 30 to 40 Gy over two weeks, leading to tumor regression in most cases.¹¹ For our patient, the palliative treatment approach included chemotherapy and orbital radiotherapy.

The prognosis for orbital metastases remains poor, with survival rarely exceeding one year. Only 27% of patients survive beyond two years.¹¹

Conclusion

Although choroidal metastases are the most frequent ocular metastases, they remain rare. The diagnosis relies on a combination of clinical and paraclinical evidence. Radiotherapy, often combined with chemotherapy, remains the cornerstone of treatment for choroidal metastases.

This case underscores the critical role of collaboration between pulmonologists, ophthalmologists, and oncologists in managing choroidal metastases from lung cancer.