Metastases mainly involve choroids, rarely, affect the retina, vitreous, and lens capsule. ¹ See more details in WHO 2023 Eye and Orbit Tumours (5th ed.) An orbital biopsy at diagnosis is not required to confirm, since most of the patients had a known history of cancer. Breast cancer, cutaneous melanoma and lungs were the most common causes of orbit metastasis (OM). Patients with OM from renal cell carcinoma and breast carcinoma were associated with the best overall survival, while OM from thyroid cancer has the worst one. ^2,3

The mechanism by which metastases reach the intraocular compartment is via hematogenous dissemination. They retain (to some extent) the histological, immunohistochemical, and molecular pattern characteristic of the primary tumors.