Secondary malignant orbital tumors are lesions that invade the orbit by direct extension from adjacent structures, such as the paranasal sinus, intracranial cavity, eye, eyelids, or ocular surface. Metastatic tumors are malignant lesions that have spread from a distant primary site, usually by a hematogenous route. The most common primary tumor sites resulting in orbital metastasis are the breast in women and the prostate in men. In children, neuroblastoma is the most common primary tumor metastatic to the orbit.
Figure 14-18 Fibrous dysplasia. The bony trabeculae are often C-shaped, composed of immature woven bone, and surrounded by a fibrous stroma.
(Courtesy of Nasreen A. Syed, MD.)
Figure 14-19 Fibro-osseous dysplasia (juvenile ossifying fibroma). Spicules of lamellar bone are set in a cellular fibrous stroma. Note the osteoblasts (arrows) lining the bony spicules.
(Courtesy of Tatyana Milman, MD.)
Excerpted from BCSC 2020-2021 series: Section 4 - Ophthalmic Pathology and Intraocular Tumors. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.