الفهرس Only 14 pages are availabe for public view
 |  | from | 234 |  |  |
| | | from | 234 | | |
Abstract
Orbital and ocular adnexal lymphoproliferative disorders account for 10-15% of orbital mass lesions. They represent a continuum of disorders ranging from benign to overtly malignant, all with a considerable risk of systemic involvement. This spectrum includes the lymphocytic lesions, plasma cell tumors, histiocytic disorders and leukemic deposits. The differential diagnosis has historically been challenging for both clinicians and pathologists due to overlapping clinical, radiological and conventional histopathological features, with variable terminologies and classifications. Nowadays, advancing immunohistochemistry allows more accurate immunophenotyping of individual clones of lymphoid cells, through identification of specific surface antigens. Evolving molecular biology provides an early and precise detection of genetic alterations through immunoglobulin or surface receptor gene rearrangement. This specific immunobiologic diagnosis allows ophthalmologists to consider the lymphoproliferative lesions as a distinct clinicopathologic entity from idiopathic orbital inflammatory disease, with much different behavior. Lymphoproliferative lesions typically present as a gradually progressive painless mass in elderly individuals, with variable proptosis, dystopia, ptosis, and less common ophthalmoplegia or visual affection. They are often located in the anterior-superior orbit involving the lacrimal gland, or beneath the conjunctiva with salmon-patch appearance, or detected as a lid mass. Fulminant orbital infiltration may occur with opportunistic infection or neuro-ophthalmic complications. Whether benign or malignant, orbital imaging reveals characteristic molding of the tumor around normal structures rather than invasion, with unusual bone erosion.