Brain Tumors Affecting the Orbit Globe and Orbit Tumors Affecting the Brain.

Brain tumors affecting the orbit and orbital tumors affecting the brain are a heterogeneous group of lesions, with histological features, behaviors, diagnostic criteria, and treatments varying from each other. Dermoid cyst and cavernous hemangiomas are considered the most frequent benign lesions, while non-Hodgkin lymphoma is the most common malignant tumor in this region. Sharing the same anatomical region, clinical manifestations of orbital lesions may be often common to different types of lesions. Imaging studies are useful in the differential diagnosis of orbital lesions and the planning of their management. Lesions can be classified into ocular or extra-ocular ones: the latter can be further differentiated into extraconal or intraconal, based on the relationship with the extraocular muscles. Surgical therapy is the treatment of choice for most orbital lesions; however, based on the degree of removal, their histology and extension, other treatments, such as chemotherapy and radiotherapy, are indicated for the management of orbital lesions. In selected cases, chemotherapy and radiotherapy are the primary treatments. This chapter aimed to discuss the orbital anatomy, the clinical manifestations, the clinical testing and the imaging studies for orbital lesions, and the principal pathological entities affecting the orbit together with the principles of orbital surgery.