Metastatic Choroidal Paraganglioma

New concepts in the diagnosis and management of choroidal metastases

The most frequent site of ocular metastasis is the choroid. The occurrence of choroidal metastases has increased steadily due to the longer survival of metastatic patients and the improvement of diagnostic tools. Fundoscopy, ultrasonography, and fluorescein angiography are now complemented by indocyanine green angiography and optical coherence tomography. Choroidal tumor biopsy may also confirm the metastatic nature of the tumor and help to determine the site of the primary malignancy. There is currently no consensus on the treatment strategy. Most patients have a limited life expectancy and for these complex treatments are generally not recommended. However, recent advances in systemic therapy have significantly improved survival of certain patients who may benefit from an aggressive ocular approach that could preserve vision. Although external beam radiation therapy is the most widely used treatment, more advanced forms of radiotherapy that are associated with fewer side effects can be proposed in select cases. In patients with a shorter life expectancy, systemic therapies such as those targeting oncogenic drivers, or immunotherapy can induce a regression of the choroidal metastases, and may be sufficient to temporarily decrease visual symptoms. However, they often acquire resistance to systemic treatment and ocular relapse usually requires radiotherapy for durable control. Less invasive office-based treatments, such as photodynamic therapy and intravitreal injection of anti-VEGF, may also help to preserve vision while reducing time spent in medical settings for patients in palliative care. The aim of this review is to summarize the current knowledge on choroidal metastases, with emphasis on the most recent findings in epidemiology, pathogenesis, diagnosis and treatment.

Bilateral choroidal tumors consistent with metastatic malignant paraganglioma

PURPOSE

To report a patient with bilateral choroidal metastasis from a malignant paraganglioma.

METHODS

Clinicopathologic case report and literature review.

RESULTS

A 68-year-old woman presented with bilateral amelanotic focal choroidal lesions. A thorough systemic work-up for a primary cancer revealed a paraganglioma (extraadrenal pheochromocytoma) and a pheochromocytoma of the left adrenal gland. Fine-needle aspiration biopsy of the choroidal lesion was consistent with metastatic paraganglioma.

CONCLUSION

Metastatic paraganglioma, although rare, has the ability to metastasize to the choroid.

Choroidal paraganglioma with metastases to the fellow eye

Purpose

To report a case of a paraganglioma in the right eye with metastatic disease in the fellow eye 3 years later.

Methods

A 70-year-old man presented with a painful amblyopic right eye; rubeosis iridis and a large choroidal tumor were found. The tumor was treated by enucleation. Pathology diagnosed the tumor as a paraganglioma. Screening for other tumors or metastatic disease was negative at that moment. After 3 years, a paraganglioma skin metastasis was detected, and screening revealed metastatic disease in the liver. Another 6 months later he was referred for tumors in the left eye, which were treated by radiotherapy. He succumbed 6 months later.

Results

Histopathology of the right eye revealed the typical image of a paraganglioma, with expression of synaptophysin, neuron-specific enolase and chromogranin. S-100 staining was positive in the sustentacular cells; staining for HMB-45, SME, EMA and pan-keratin was negative. Microscopy of the tumors in the skin and liver 3 years later showed a dedifferentiated tumor with the same immunological characteristics, but with higher Ki67 expression and more mitoses.

Conclusions

This report documents a very rare choroidal paraganglioma which presented clinically as a melanoma. The patient succumbed 4 years later to generalized metastatic disease. No other primary paraganglioma was found; however, paraganglion cells in the eye have never been described.